I used to play Furcadia all the time just a graphical chat pretty much. Diablo II also took one of my summers, great game.
I used to play Battlefield 2142 and NY Mafia, whiche both are decent games, but havent got the time to play anymore lately :/
I played Runescape a lot, mainly because my friends did. It's fair to say we totally abused that game. While i was running a clan of level 60-ish Pkers, my friends were auto-ing and luring millions. We always shared accounts, and as a result, most if not all are banned. I also played Guild Wars, which i thoroughly enjoyed. I'm eagerly awaiting Guild Wars #2. Other than that, i enjoy my FPS's; Battlefield 2, Counter Strike, Americas Army..
woww, i m completely addicted of the NFS most wanted and Counter strike, its the great developed games which had fun to play online....