Phantasy Star Online (Cube).. for.. around 1000 hours.. IN OFFLINE MODE! XD (Played Splitscreen with friends back then)
edit: Oh, i DID play WoW, so yeah, dunno how much, but surely 3 Years for at least 3-4 Hrs a day.. would mean 'at least' 2000 Hours. (Id say its more like 3,5k, but thats just a guess)