The first forum I signed up to wasn't very well known. It was basically a forum to discuss a map project for Warcraft 3. They had a good community there, but sadly it went down when the original developer stopped working on it.
Then I remember joining a number of forums I didn't really post on. I realised that when you have one good community, and the site has a general discussion forum, there's not much point in joining up in other places. Unless they have something to offer of course.
