Ultima Online was the first MMORPG created. It started the whole genre. Yes, there were MMORPGs before WoW. World of Warcraft and other MMORPGs honestly are nothing compared to this game. I've been playing UO for nine years, and I still find myself going back to it. I don't think I'll ever free myself of the addiction; there are too many memories tied to this game. It's changed a lot throughout the years. If you haven't played it, though, it's still worth checking out. I recommend that you play on the free servers. The official servers aren't good at all anymore.
Download the game for free (legally) here: http://www.uo.com/uoml/downloads.shtml
Download the game for free (legally) here: http://www.uo.com/uoml/downloads.shtml