Lets see - I used to play some text based MMOs in AOL chat rooms back in the day, but as I don't remember the actual dates for those I'll let it go!
My first MMO "game" was Everquest Online Adventures for the PS2. The game was released in 2003. I've sinced played:
City of Heroes
Final Fantasy XI
World of Warcraft
Age of Conan
Star Trek Online
There are probably others in there I've forgotten, but you get the drift! Nerd to the core.