Only three mentions of Aiyon. Anyway, here's what I've been able to find.

EoFF - Joined August 2000. Have never spent longer than a few days without browsing it since that day.
ASC - Joined uhm. I'll check later. Ages ago, though. I'm a come-and-go member there now, but I love the place, it's great fun.
FFFederation - Joined uhm. I'll check later. Robb's board that never took off although it had some pretty amusing threads and a couple of references that will remain in my mind forever. keke.
Aiyon - Joined the day it was made around February 2003 since I run the place. If EoFF is my home, Aiyon is my shack. Something? and LJ Forums and EoffFF aren't really anything close to what Aiyon is to me. Basically a hangout board that I use for my own purposes and projects. 'Aiyon' is the name of a world I created and continue to work on.
CricketWeb - Joined March 2004. Probably my 'second forum' after EoFF with regards to activity, the only EoFFer that I know of that goes to CW is Dan (Majin / Loki) 'cause I told him to. But yeah, CW is a great cricket forum, and I'm really involved in a simulation league they have going there. I'm vice captain of CW Green in the dev league and have played an international game too. Although I suck as a player, now, I'm still an awesome vc. ;D
FFInfinate / Final Gaming - Was invited to join on the day it opened and took up the offer, have been a come-and-go member ever since. <3 Skwowwy.
tGA - Joined ages ago. Can't remember. I'll check later. I host tGA and work as a technical (well, vB technical) admin there. RP board that I often actually enjoy.
The Basement - Joined the day it started. I host TB and work as a technical (well, vB technical) admin there. I might start posting there semi-regularly again soon... since I'm all lovey-dovey lately. Heh. =x
Fool's Gold - Joined donkey years ago and then got my account deleted after making hundreds of posts on my first day (seriously). I am an advisor of sorts at this forum now, with staff forum access and whatever. It's pretty much the only place I post there, anyway.
The Admin Zone - Joined October 2004. I lurk there more than anything, but every now and then I'll post my thoughts. This is a board where many forum admins go to and talk about adminny stuffs, managing communities and whatnot.
LJ Forums - Another one of mine. Forum for LiveJournal users that had a lot of potential, but, sadly, I lost motivation for the place and eventually let it die off. It did however generate enough traffic to warrant a shoddy old placeholder guy to buy the domain and use it for his shoddy old placeholder site, so yay. I still have the forums database for LJF, I think.
Eyes off Final Fantasy - Can't remember when I made it, I'll check later. Mock EoFF board with a mock staff. Good fun for a while but eventually died out. I think I still have the database on my PC.
Something? - Elitist board I made way back. xD Well, not elitist so much as "friends only" or something. Great fun while it lasted. Some brilliant threads.
Online Survivor - Linus and I were on the 2nd or 3rd one of these. I think they were run by Mr Rocko?
vBulletin - Joined September 2003. If anyone's likely to post at vB for EoFF's issues, it'll probably be me. I think I'm the only person on staff who posts there at all, actually. Very sporadically, though. I only have 83 posts in a year and a half.
OTHERS INCLUDE: FFLegend, All For The Music, FFOnline, FFWA, HotHardware, All World Final Fantasy, WebHostingTalk, Trillian, Civ Fanatics, AdAware. And I think some Warzone2100 board, somewhere. Along with many more, since I tend to join forums just to ask a question and then leave quite once it's answered.

Note that whenever I said I'll check something later that I'm probably lying.