What Steam Game Have You Spent The Most Hours Playing?

Arma 2 OA i have 400 hours almost lol

gmod, over 500 hours.

36 hours is NOTHING

CSS - 215 hours and 184 the Binding of Isaac - 184 hours

Skyrim currently, but I think The Binding of Isaac might be the most soon.

Zen of Sudoku. 300+ hours. I like solving sudokus, okay. :(

Dota 2 663 hours

LA Noire - 108 hours.

FTL: Faster Than Light - 57.9 hours logged while online on Steam and at least 30 hours logged while offline.

(Second most hours played on Steam would be Don't Starve with 35 hours online and 20+ hours offline)

Team Fortress 2 - 2671 hours

It seems I currently have longest playtime in Ys Origin, clocking 36 hours. I just love that game, want to play it even more ^~^

Dota 2 - 1 505 hours

it says on my profile that I've played 1900 hours of tf2, but I know I've logged more time than that. A lot of the hours for games I played many years ago on my old computer are not attributed to my profile.

dota 2 454 hours

Orcs Must Die! 2
123.0 hrs on record

Defense Grid will be my most played game soon. 110 hours already and I'm going for all the achievements.

TF2 for 898 hours, but most of that is idling so doesn't count. Alien Swarm would be it, with a little over 200 hours so far.

Garry's Mod - 586hrs :3

Skyrim, 176.3 hours

Civilization IV, almost 50 hours... I spend most my time on MMORPGs and they're only seldom on Steam.

2494 hours in Team Fortress 2.

Garry's mod. 2492 Hours

Simcity 4 with 18.5 hours. Eventhough that's nothing i've got 1000+ hours before someone gifted it to me on Steam.

A non-Steam game in my Steam Library:
2333 HOURS.
The game is called Transformice.

A steam-bought Game:
174 HOURS
Terraria

Skyrim, 183 hours or something

Awesomenauts, 643 hours. Nothing comes even close, not on steam.