I started out with UO a few months after its release. No gaming experience will ever come close to that. The EQ'ification/carebear'ification of UO with the introduction of mirrorshards Trammel/Felucca changed the game so much that i stopped playing. I didnt have the heart to close my account until 6 months ago..
Been playing almost all the early MMORPGs but only DAOC made me stay for more than 6 months. Right now i am on a break from DAOC, but i am contemplating returning. I hate the Trials of Atlantis though. The prospect of taking a character through the Masterlevels just makes my body go numb.
(Once, or rather twice, is MORE than enough )
MMORPGs is the future of gaming/entertainment imo. I am still waiting for the perfect one though