I reactivated my WoW account earlier this month, only to cancel it again three weeks later I can't dedicate myself to MMOs anymore, I'm just sick of them. Sad that I didn't decide this before I bought WotLK.
But as it may be, my MMO experience:
Everquest 1 (played to lvl 5, lol)
Everquest 2 (played the trial, it sucked)
Everquest Online Adventures (the PS2 version, played to lvl 20 shadowknight)
Final Fantasy XI (got to lvl 30, goldsellers ran the economy, hard to make gil without buying using IRL $)
Lineage II (Private servers with ridiculously enhanced rates)
World of Warcraft (played to lvl 70. IRL friends quit playing after high school, not much fun after wards.)
Guild Wars (boring)
Auto Assault (beta tester, twisted metal in an MMO format, minus the fun.)