Ah, forums. In the grand tradition of the classical civilisation concept that gave them their name, SF&F forums are enlightened places of civilised discussion and debate, where everyone's opinions are respected and the partipiants enjoy partaking in a mutual exchange of ideas for their mutual enrichment.
Okay, maybe not, but relatively SF&F forums are, believe it or not sometimes, among the best out there. Venture into a computer game or TV-based forum, and it won't be long before you're decrying the state of the education system amd the rise of functional illiteracy, whilst pondering if you should be hiring a bodyguard given the reaction you provoked when you very gently suggested that maybe, just maybe, the new Doctor Who isn't quite the single most fantastic thing since sliced bread.
My forum of choice is Westeros. Technically, this is supposed to be the forum dedicated to George RR Martin's A Song of Ice and Fire series. However, since new novels in the series come out at rather irregular intervals, the fanbase on the forum spends enormous amounts of time discussing other books and authors, as well as TV shows, games, politics etc. You know a forum has 'made it' when increasingly more people are joining up to take part in the discussion who have never read the author the site is supposedly supporting. With nearly ten thousand members, Westeros is also one of the biggest forums out there. The quality of discussion is usually high, and you can find me hanging out there most days, whilst authors such as Peadar O'Guilin, Joe Abercrombie, Scott Lynch, Pat Rothfuss, Brandon Sanderson, Brian Ruckley and Richard Morgan have been known to stop by from time to time.
My oldest forum is Wotmania, specifically the 'Other Fantasy' subforum. I first visited this forum ten years ago, not long after it was established, and lurked there for many years. The quality of discussion is likewise high, and unusually for an epic fantasy board discussion of other types of genre is quite frequent. Few people would probably credit a Robert Jordan board for hosting so much discussion of Hal Duncan, M. John Harrison and Jeff VanderMeer. Interestingly and conveniently, the Other Fantasy subforum lumps TV, films and books together, making navigation a breeze compared to some other forums. On the other hand, the forum software is ancient, and the site has an extremely old-fashioned look to it these days.
Malazanempire is of note for Steven Erikson fans who haven't got a clue what is going on in the books. The posters there are extremely knowledgeable of the series and if you poke around you'll find my map of the entire Malazan world, as approved by Erikson himself (although it's not canon and I had to guess at a lot of the stuff, it's apparently pretty close).
SFX is the forum of the British SFX Magazine and is notable for its heavy British bias towards SF&F. Whilst I can't recommend the book discussion section too much (it's often dead for weeks at a time, aside from the 'what are you reading now?' threads), the TV discussion is pretty interesting and it's one of the few forums I've come across with a dedicated anime discussion subforum.
SFFWorld is one of the bigger multi-topic forums out there. Not dedicated to any particular author or subgenre, the breadth of discussion is impressive and the mods and admins know their stuff. There are two criticisms. First off, there sheer mass and number of subforums (14 of them) is a bit off-putting when first confronted. I can't help but feel that other forums have handled having a large breadth of discussion topics somewhat more elegantly. The split between the SF and Fantasy subforums, one of the few boards to do this, also means slightly more work for the casual browser as he has to move between both forums. There are also technical issues. Possibly down to the sheer volume of topics out there, the board is sometimes slow to load and posting a reply can take a long time (often you can hit 'Post Reply', go off to make a cup of tea and come back to find it still hasn't gone through). Despite these minor issues, the quality of discussion on the board is high and there quite a few authors who participate in discussions there, including the likes of Gary Wassner, James Barclay and Scott Bakker.
In terms of membership (although it should be remembered that the membership of any board can be misleading, as old, inactive accounts and alts belonging to the same person are usually counted alongside current accounts), Chronicles Network is allegedly the biggest SF forum out there. However, it's clunkily designed with the number of subforums verging on the insane. Whilst they do keep SF and Fantasy together (but separate Horror from both), they have separated out reviews, a curious decision given that reviews are a primary driver of discussion. Again, however, there is a lot of great discussion to be had there.
Other authors such as Paul Kearney and Brandon Sanderson also run their own forums where interesting, decent discussion can be found. Scott Bakker's forum, Three-Seas, has recently made a bit of a comeback from a long period of quiet and has had a bit of smart makeover. Good to see this board gearing up after the three-year-drought of new material from the author. The new-ish board dedicated to Peter F. Hamilton's works, The Unisphere, is also a good read for those looking for more info on Hamilton's works.
Okay, so that wraps that up. I may continue to update the list as time goes by as other, interesting forums are pointed out.