Yog Sothoth
Community forum site for HP Lovecraft fans and players of role playing games based around the Cthulhu mythos.
Story Games
A popular forum / community about story games (which arguably either are or are not role-playing games).
d6 Online
A community forum focused on various products based on the d6 system, an Open Game License game that originated with the West End Games Star Wars Role Playing Game and Ghostbusters games.
EN World
Popular news and forums portal for role-playing games.
Original D&D Discussions
Forum devoted to the earliest iterations of Dungeons & Dragons, retro-clones and friends.
The Acaeum
The D&D Collectables forum. If you want to know what its worth, check here.
The RPG Haven
General role-playing game forum with commercial postings and not specifically dedicated to a single RPG.
Dragonfoot
Large, old school forum dedicated primarily but not exclusively to AD&D 1st Edition.
RPG.net
High volume, heavily moderated RPG forum and news site.RPGnet is the oldest & largest independent roleplaying site on the Internet. It was founded in 1996 by Emma Antunes.
theRPGSite
RPGPundit's popular RPG site where you can speak freely with the understanding others will reply freely. SJW and story-game cultists beware.