So...about a week and half ago, I hit level 60 on my human rogue in World of Warcraft (screenshot of the event). I picked a hellishly easy area to level in, but hey...the result is the same, right? ;-)
Total time to reach level 60: 21 days, 26 minutes and 45 seconds. Yes....504 hours were spent playing a game. :-( Granted, I started playing last year (around October I think), but still...that's a lot of hours burned playing a game.