Personally I've only been really active in one other forum before (about Ghostbusters), although I've joined a few others (about C64, a movie comunity,...).
I still check in those forums from time to time, but abandonia is the first forum I really stuck with (although for some strange reason I don't like AR too much).

How about the rest of you?

For me I've joined a bunch of forums all over the place, most of the time though what ends up happening is I just end up reading and not posting much, only real forum I used to be fairly active at was gamefaqs over on some of the game boards, now not as much, mostly been abandonia now and AR. :D

It was my first and I'm only active on two of them, AR and this one.

I'm also on The Trenches forums, but not much.

i have been on some game forums before. and i used to be on the runescape forums a lot (please dont hate me for that) also i used to go on the kazaa lite k++ chatlines (not a forum though i guess) but this is my faveorate. the admins dont seem to have god complexes. the variety of people is cool. get some pretty interesting stuff from here

I've been truly active on only one forum before abandonia, that was emuforums.com(2 years before I joined here) where I rejoined again not long ago...
I was also a member of a few Croatian forums but I didn't make more than 50 posts when you combine them all together...

I've been active at three forums before this one. Some forum about the game Revolution, a forum about the movie The Thing, and NMA, in that order. I still post at NMA once in a while.

I started a forum for my SCA group in Virginia, because I was the group's webmistress for a while. It was mainly used for announcements and posting meeting minutes, though, or coordinating rides to events. We mostly stuck to the mailing list for group conversation purposes, hehe.

Other than that, I've found most forums to be really not that great. I use them for information collecting purposes, but not so much to be a part of the community. For the most part, they're dead, or if not, they're filled with flame posts, or spam.

Abandonia had a nice group of people, and the pace wasn't too fast or too slow, so I stayed. :D

Abandonia the first site I ever registered to.
I did register to anywhere.i.am, but for some reason my account there never worked. So I guess Abandonia is also the only forum I'm active on.

Well, my name is from the Total Annihilation official forums back in the day, but I'm active on the AirBuccaneers forum and I used to use my old UT2k4 clan's forums, but they seem to have disappeared somewhere *shrugs*

First forum I've joined. Active here and in AR. I used to be moderator in another forum created by Puffin, but it sadly fell into oblivion.