Well I'm not the most original with my responses, so I'll state I used to play World of Warcraft as well, quite eagerly. But I never really played it to get the penultimate ubergear and slaughter end-raid bosses in under a minute. I found a nice guild fairly early on when I was just starting, and these people became my friends. I ran an occasional dungeon with them and whatnot, and even a raid or two, but it was knowing those kind people that kept me coming back.
It's been a while since I stopped playing though. I'll probably start again with Cataclysm, just to see what's new. Of course if Blizzard implemented some sort of solo mode for raids and dungeons, with no true gear rewards, simply to experience the story, I might be tempted to play even longer...
Yeah, I know it will never happen.
Anyway, off that subject. Can I use The Escapist as my other example? That, and games with a heavy focus on user-created content, that is, if the tools provided are worth looking at.