I used to spend
8-12 hours daily playing WoW.
And no I'm not a fat guy living in my mom's basement, it just took me a long to realize how utterly pointless it was. That, and many other MMO's.
I think part of the problem with many MMO's is this: you're paying for a subscription... so you almost feel obligated to play.
I liked the subscription-less concept of Guildwars, but when I tried it the gameplay seemed kind of hollow. GW2 sounds neat though.