I played Everquest for a while when it first came out, but as friends stopped playing I got bored and stopped too. Then we all tried Star Wars Galaxies, but that didn't hold our interest too long.
Now I and a couple of other friends have been playing Lord of the Rings Online for almost 2 years. We did the betas, and bought the lifetime memberships. There's only a small group of us, but we're still playing every Thursday and Friday night. I don't play quite as much as they do because I play console games more.
It's a good game for playing with friends, but I'm not one to try to level all 5 of my characters by doing the same quests over and over. I am surprised though that it has kept my interest as long as it has- it's been waning the last month or two, but there's an expansion pack coming out this month (and they typically add new free content every few months).