49. H.P. Lovecraft
Classic 1920s writer, best known for his Cthulu Mythos series of stories and novels, which other writers later expaned upon.
48. Mervyn Peake
The author of The Gormenghast Trilogy. After The Lord of the Rings, arguably one of the most important, 'classic' works of fantasy of the 20th Century.
47. Jules Verne
19th Century early SF author, best-known for 20,000 Leagues Under the Sea and Journey to the Centre of the Earth.
46. Alastair Reynolds
British SF author, best-known for his Revelation Space series of novels, novellas and short stories. Chasm City is his finest work.
45. Neal Stephenson
Major post-cyberpunk SF author, best-known for Snow Crash, The Diamond Age (soon to be a mini-series), Cryptonomicon and the enormous Baroque Cycle.
44. Clive Barker
British horror-fantasy writer, author of novels such as Weaveworld and Imajica, but probably best-known for being the creator of the Hellraiser series of movies.
43. Jim Butcher
A relative newcomer, but one who has made a major impact with his Dresden Files series of urban fantasies and his Codex Alera fantasy sequence.
42. Tad Williams
American fantasy and SF author whose Memory, Sorrow and Thorn trilogy is usually cited as the first work (excepting Stephen Donaldson's Thomas Covenant series a decade earlier) of epic fantasy explicitly aimed at adults, with more interesting and deeper themes than the Brooks/Feist/Eddings school of fantasy which predominated in the 1980s. His series of Otherland SF/fantasy hybrids is his strongest work to date, although it suffers from his continual problem of overwriting. His current Shadowmarch Trilogy, which returns him to epic fantasy, has received mixed reviews.
41. Kurt Vonnegut
Classic American SF writer, best known for Slaughterhouse Five.
40. Trudi Canavan
A relative newcomer and one of the new wave of Australian and New Zealand SF&F writers to make an impact on the genre. Her Black Magician Trilogy was a huge success when published in the UK a few years ago.
39. Michael Moorcock
One of SF&F's most prolific and interesting figures, also noted for producing interesting works of mainstream fiction. The centrepiece of his work are the Tales of the Eternal Champion, a massive collection of stories and novels spread across multiple worlds, universes and incarnations of the central hero. Of those tales, his Elric of Melnibone series is the best-known. Mother London and The Dancers at the End of Time are among his other works.
38. David Eddings
Although his later novels - particularly the near-unreadable Tamuli series and everything published since - can best be employed for cat litter purposes, Eddings' Belgariad series was a gateway to the genre for many young readers, and continues to do so since it was re-purposed as a YA series. Eddings later acknowledged that his wife Leigh, who sadly passed away last year, was his collaborator and co-writer on all of his fantasy work.
37. Alan Moore
Probably the most iconic writer in modern comics publishing, having written The League of Extraordinary Gentlemen, From Hell, V for Vendetta and the seminal Watchmen (the movie version of which will be released in June 2009), although he got his break by writing for Doctor Who Magazine's comic section and 2000AD. Infamously scathing of the film adaptions of his works, Moore is one of the defining SF&F authors of the modern age, and Watchmen should be required reading in the genre.
36. Orson Scott Card
An interesting SF&F author whose popularity is based mainly on his extremely accomplished mid-1980s novel, Ender's Game. His Alvin Maker and Homecoming series have also proved popular. In recent years Card has mostly spent his time churning out additional Ender books of variable quality, and his most recent stand-alone, Empire, may rank as one of the worst novels published by a reputable publishing house this millennium.
35. Stephen Donaldson
Major SF and Fantasy author whose Chronicles of Thomas Covenant series is generally held to kick-started the modern fantasy boom when the first volume Lord Foul's Bane, was published within a few weeks of Brooks' The Sword of Shannara in 1977. Although Covenant is Donaldson's best known series, his SF series, The Gap, is probably his most accomplished work.
34. Gene Wolfe
A surprisingly low entry for one of the best speculative fiction authors of the modern age. The Book of the New Sun is a stunning achievement, a work to rival Gormenghast and The Lord of the Rings for significance and resonance, and even more startlingly its sequel series are important works in their own rights and not mere cash-ins. Still producing interesting work, Wolfe should frankly be in the Top 5 of this list at the very least, but such are the ways of polls.
33. China Mieville
An author who is something of a breath of fresh air in the genre, whose Perdido Street Station kick-started his quasi-horror, semi-steampunk SF/Fantasy hybrid Bas-Lag series of very loosely connected novels (also incorporating The Scar and Iron Council). Outside of this series he has published a very fine urban fantasy (King Rat), an exceptional YA novel (Un Lun Dun) and an excellent short story collection (Looking for Jake). Still in his 30s, Mieville's greatest work may still lay ahead of him, although what has come so far already marks him as one of the best SF&F authors of the new millennium.
32. Raymond E. Feist
Feist's 1982 novel Magician remains a readable and exhiliratingly entertaining epic fantasy novel incorporating the clash between two worlds (the medieval Europe-influenced Midkemia and the Oriental-stylised world of Kelewan) when they are linked by a magical rift in time and space. All but one of Feist's subsequent 26 novels have been set in the same universe. His Empire Trilogy, cowritten with Janny Wurts, is an excellent dynastic fantasy set on Kelewan, and shows the freshness and originality that epic fantasy can still achieve when it moves outside its comfort zones. His later novels reached their zenith with the bloody war novel Rage of a Demon King, but with the exception of another collaboration with William Forstchen (Honoured Enemy) all of his later novels have been disappointingly pedestrian.
31. Lois McMaster Bujold
American SF author, best-known for her Miles Vorkosigan series of space operas which, sadly, I have not read yet.
30. Roger Zelazny
Another major 'classic' SF author, best-known for the lengthy Amber sequence of fantasy novels, although his Lord of Light and Damnation Alley are also highly accomplished.
29. Anne McCaffrey
American SF author, currently resident in Ireland. Best-known for the Dragonriders of Pern and The Ship Who... series.
28. Steven Erikson
Canadian fantasy and SF author, best-known for his enormous Malazan Book of the Fallen series which is now one of the most dominant epic fantasy series on the market. He has also written an SF novella (The Devil Delivered) and has worked on a web-based SF series, The Dark.
27. William Gibson
Major SF novelist best-known for Neuromancer and is sequels and is credited as the originator of cyberpunk, although his more recent work has been dominated by near-future and mainstream novels.
26. Guy Gavriel Kay
Another Canadian fantasy author, but whose credentials are impressive: he got his first break in the genre when he assisted Christopher Tolkien in editing The Silmarillion for publication in 1977. His earliest work, The Fionavar Tapestry, is also his most traditional, but he is best-known for producing four classic stand-alone novels that evoke particular times and places in the real world: Tigana, A Song for Arbonne, The Lions of Al-Rassan and The Last Light of the Sun. His Sarantine Mosaic duology and Ysabel, a semi-sequel to the Fionavar series, are also of note.
25. CS Lewis
Classic British SF and fantasy writer, best-known for The Space Trilogy and The Chronicles of Narnia, as well as his Christian views that influenced much of his later work, most controversially in the final Narnia book, The Last Battle.
24. Diana Wynne Jones
Author of numerous SF and fantasy books for children and adults alike, although her most notable work may remain The Tough Guide to Fantasyland, a hilarious guidebook to the tropes of the epic fantasy subgenre. Anyone who sets out to write an epic fantasy these days without consulting this book first may find themselves on very shaky ground.
23. John Wyndham
Classic British SF author, best-known for his enormously influential The Day of the Triffids, but also wrote many other books of note, including The Chrysalids.
22. Philip Pullman
British author of fiction for children, some of it falling into the SF&F genre. His most notable work is the hugely successful His Dark Materials Trilogy, which can be seen as a thorough rebuttal of Lewis' Narnia series but also a major and influential work in its own right.
21. Robin Hobb
One of the biggest-sellers of epic fantasy in recent years, with her 'trilogy of trilogies' (The Farseer Trilogy, The Liveship Traders and The Tawny Man) attracting a huge number of fans, although her more recent Soldier Son Trilogy has attracted more mixed reviews.
20. Stephen King
One of the biggest-selling authors of all time, with his total lifetime sales likely to be incalculable. He has written many works of horror, some supernatural and some not, as well as a smaller number of pure science fiction and pure fantasy stories. However, almost all of his work takes place in the extended universe of The Dark Tower, with characters and motifs repeating themselves across many different books. The Dark Tower itself - seven novels written between 1970 and 2004 - has divided readers due to its highly controversial concluding volume.
19. Ray Bradbury
Major American SF novelist and writer, best-known for Farenheit 451 and The Martian Chronicles.
18. Arthur C. Clarke
Probably the most famous SF writer of all time, the author of several seminal SF novels (Rendezvous with Rama, Childhood's End, The Fountains of Paradise, The City and the Stars and A Fall of Moondust most prominent among them) and the co-writer of the movie 2001: A Space Odyssey, along with director Stanley Kubrick. He also had a huge impact on popular science through his 1970s and 1980s documentaries and TV series (most notably Arthur C. Clarke's Mysterious World). He also popularised the idea of geostationary communications satellites in the 1940s, which has led to the geostationary orbit also being dubbed the 'Clarke Orbit'. Clarke passed away earlier this year at the age of 90.
17. Robert Jordan
The author of the hugely successful Wheel of Time series which, despite a major lapse in quality in its eighth through tenth volumes, is nevertheless a major work which popularised the idea of SF&F series lasting more than the traditional three volumes. Despite longeurs, the series is notable for its themes of the mutability of knowledge and the interrelationship between legend, myth and history. Jordan died of the blood disease amyloidosis last year having begun the twelfth and final Wheel of Time novel, which will now be completed by Brandon Sanderson for publication in late 2009.
16. JK Rowling
The most successful author of the 21st Century, whose seven-volume Harry Potter series has sold some 350 million copies worldwide and been credited with interesting an entire generation in reading.
15. Robert Heinlein
American SF author, one of the 'Big Three' alongside Clarke and Asimov, best-known for Stranger in a Strange Land and Starship Troopers.
14. Frank Herbert
The author of Dune, the single biggest-selling SF novel of all time. His other work, particularly the five Dune sequels, are variable in quality and the 'tribute' novels by his son and Kevin J. Anderson should be avoided at all costs. But Dune itself remains a powerful and unique work of science fiction.
13. Peter F. Hamilton
British SF author whose work encompasses near-future detective thrillers set in a Britain flooded by global warming (The Greg Mandel Trilogy) and enormous space operas spanning dozens of planets and thousands of pages (The Night's Dawn Trilogy). His fast-paced, page-turning style mixed with a tremendous capacity for invention (a PFH book is "Fifty lesser SF novels rolled into one," according to critics) has won him enormous success and legions of fans. Hamilton is at his best writing gigantic blockbuster space operas with intelligence, and The Night's Dawn Trilogy may be the best work of 'pure' space opera since the original Dune.
12. David Gemmell
British fantasy author who started his career with Legend. He eventually wrote some thirty novels which combined hack 'n' slash fantasy adventures with musings on the human condition, and he was capable of tremendously cutting observations and poetic turns of phrase when required. Tragically, he died two years ago from a heart attack just before completing his finest work to date, a historical trilogy based on the fall of Troy, although the final novel was ably completed by his wife Stella.
11. Ursula K. LeGuin
Still one of the most influential of all SF and Fantasy novelists, best-known for The Left Hand of Darkness and the Earthsea series.
10. Robert Rankin
Prolific British comic fantasist whose work owes a lot to the zany observations of Spike Milligan. His books come across as 'tall tales' rather than conventional novels. He is variable in quality (the Armageddon Trilogy is vaguely amusing but nothing more, whilst his Hugo Rune series is hilarious), but usually has some interesting ideas going on.
9. HG Wells
One of the most important formative writers of SF, the author of The Time Machine, The War of the Worlds, The Island of Doctor Moreau and The Invisible Man, although his greatest success was probably depicting the use of nuclear weapons in The World Set Free, written some thirty years before the testing of the first A-bomb.
8. Philip K. Dick
A major SF writer of the 1960s and 1970s, whose novels were enormously influential. His best-known works are Do Androids Dream of Electric Sheep? (later filmed as Blade Runner), The Man in the High Castle, The Three Stigmata of Palmer Eldritch, Ubik, A Scanner Darkly and Flow My Tears, The Policeman Said.
7. Iain M. Banks
British science fiction author who has also had a highly successful career as a mainstream author (writing under the name 'Iain Banks'). He is best-known for his creation of the Culture, the ultimate utopian society, and its depiction in major SF novels such as Consider Phlebas, Use of Weapons and Player of Games. His non-Culture SF works, Feersum Endjinn, Against a Dark Background and The Algebraist, have not been as notable. His mainstream work, which sometimes touches on SF&F tropes through fantasy and dream sequences, most notably in The Bridge, is also accomplished, most notably his classic debut novel, The Wasp Factory.
6. Isaac Asimov
The most prolific author on this list, with some 500 books to his name. In SF he was best known for his enormous future history sequence incorporating the Robots, Empire and Foundation series into a massive framework spanning over 20,000 years, and also for the short story Nightfall which was voted the best SF story of all time as recently as the 1980s. He also wrote mainstream detective fiction and dabbled with fantasy, most notably the Azazel series of comic fantasies, but he will be best-remembered for coining the Three Laws of Robotics.
5. George RR Martin
The highest-ranking non-British author on the list. GRRM has been writing in the SF&F genre for forty years, penning some highly-accomplished short fiction from the late 1960s onwards (including Nightflyers, Sandkings, A Song for Lya and many more). He started writing novels at the end of the 1970s with Dying of the Light, and achieved a major success with the excellent Fevre Dream in 1981. However, the commercial failure of the subsequent The Armageddon Rag led GRRM to get work in Hollywood, where he worked on The New Twilight Zone and Beauty and the Beast. At the same time, he won new legions of fans by cowriting and editing the lengthy Wild Cards series of 'realistic' superhero stories. In 1991 he began work on his Song of Ice and Fire series, one of the most critically-acclaimed series (SF or fantasy) of modern times, which now extends to four novels and two novellas with more on the way. Whilst A Song of Ice and Fire has to some extent eclipsed his earlier work, the release of his Dreamsongs collection has demonstrated his versatility as a writer.
4. Douglas Adams
Comic SF author who got his start by scripwriting for radio and for TV series such as Doctor Who, where he was a script editor in the late 1970s. His own best-known creation is The Hitch-Hiker's Guide to the Galaxy, which began as a radio serial and became a BBC mini-series, five novels and a disappointing movie adaption. He also created Dirk Gently's Holstic Detective Agency (which was supposed to be an ongoing series, but only reached two novels and a third half-finished at the time of his death). Adams suffered from writer's block for much of his working life, explaining his low output, but the work he did produce continues to entertain new generations of SF readers.
3. Neil Gaiman
Neil Gaiman rose to prominence in comics, most notably with The Sandman, which ran from 1989 to 1996. When taken as a single, 2,000-page work, The Sandman is an astonishing accomplishment and one of the most significant works of fantasy of the modern age, an epic combining myth, dreams and fantasies into a surprisingly tight narrative surrounding Morpheus, the Prince of Dreams. Outside of this work, Gaiman is best-known for his novels Good Omens (co-written with Terry Pratchett), American Gods and Stardust (later adapted as a successful movie). The Graveyard Book, a macabre take on The Jungle Book, is his latest novel, due at the end of the year. He also created the television mini-series Neverwhere, which became a successful novel and comic book.
2. JRR Tolkien
The creator of Middle-earth and the writer of The Lord of the Rings and The Hobbit probably needs little introduction here. No author is more significant in the development of 20th Century fantasy or more influential in the number of other writers they have inspired, whilst the three-part movie adaption of his Middle-earth stories (soon to be joined by two more) is the biggest success story in cinema this century.
1. Terry Pratchett
A surprising winner? Possibly not. Pratchett has written some 30 novels set in his Discworld setting and another dozen outside it, making him one our most prolific authors. With nearly 60 million sales to his name, he is also the biggest-selling living author in the genre with the exceptions of Rowling and King. However, Pratchett combines success with almost continuous critical acclaim and increasing mainstream literary respect. His books are sometimes just pure comic entertainment, but more often than not they are also keen-eyed satires and observations on culture, history and the world, displaying a formidable intelligence and attention to detail,a ll of which have won him plaudits including regular comparisons to Dickens. Easily one of the most significant authors of fantasy of our time.
So there you have it. A fairly decent list, all round, although I can hear various cries of "But what about..." and "WHO is number one?" across the Internet from here. As always, there are some notable absences: a list that has Douglass, Goodkind and Eddings on it cannot spare room for Kearney, KJ Parker, Celia Friedman or Walter Miller? Disappointing.