I don't remember what has been my very first MMO, could have been UO. But what first pops to my mind is my first contact with SWG: utterly boring! I couldn't think of a game more boring than SWG at that time Logged in during beta, somewhere in the desert of Tattooine with no intention where to go, what to do or any other players around. I ran up some dune, saw a village, found some villagers not responding to my greetings, logged off and didn't log back in until some couple of years later.
TOR I logged in and had fun the very first moment.