My first MMORPG was Everquest. My stoner neighbor introduced it to me in '99 when I was still in the Navy and I got hooked. He played it day and night, 24-7, so it looked fun to me. I didn't really get to play it for real until I left the Navy in late 2000.
The thing I enjoyed the most about it was exploring the world and discovering new quests and areas to adventure in.