Fnord
SasqWatch
You have 1600 Steam games?!!!!
Bundles bundles and more bundles. After a while you end up with a lot of games. Also, it's not quite 1600, the way steam counts games, it also considers all free games that I've tried to be "owned", and also certain DLC get their own entry on that list.
The top game is DOTA 2? Oh Fnord, how COULD you!? Wait… you were letting somebody else use your account, right? That's it. That must be it. Phew!
P.S. Interesting that 4X games seem to be doing about as well as RPGs in our top hours lists.
Sorry to say it, but that's all on me. It's actually a really good game, if and only if you play with 4 (or 9) friends.