The only game I play online anymore is World of Warcraft, but that is only because I love to play with my friends. Lucky for me I have a solid group of close friends that I have gamed with for over a decade. I've tried other MMOs without them and it is not the same.
I gave up on traditional online gaming after Rainbow Six Vegas 2. I spent more time muting and blocking people than I did playing a match. The good thing about WoW is it is fairly easy to block out the idiots. Just /leave trade chat.