What game have you spent the most hours playing on steam?

I had a look today and was pretty surprised to see I have spent over 155 hours playing Company Of Heroes. Second best is Bad Company 2 at 86 hours. I'm kind of glad steam doesn't show my World Of Warcraft or Starcraft 2 hours. 
 
Fuck, I have too much free time :S

Audiosurf with 26 hours. 
 
I need to play more Steam games.

Modern Warfare 2... about 800 hours.
 
 
Christ, what was I thinking?

Played Football Manager 2010 for 129hours. Only game I have on Steam now also :P.

Been playing TF2 since the start of the Beta.  I don't know if I have logged as many hours as I did on UT2004 (pre-steam) because my work schedule was much lighter while that game was out but its been an awesome 3 years on TF2.

Dragon Age, something like 150+ hours between my two different accounts.

Team Fortress 2
Counter Strike 1.6
Counter Strike: Source
Mount and Blade: Warband
Empire: Total War

Team Fortress 2: 740 hours. I idled for hats.

Dragon Age: Origins - Ultimate Edition at around 30 hours.

Counter Strike: Source - 26 Hours

Mw2, 150 hours or so

Star Trek Online- 200+ hours @_@

Dragon Age: almost 300 hours 
Mass Effect 2 : 131 hours 
Battlefield Bad Company 2: 183 hours 
 
Yeah, I had a lot of free time last year.

Plants vs Zombies. About 155 hours, but considering how many hours I left the game on Zen Garden mode I'd say the real total would be closer to 120 hours.

Team Fortress 2 by far. 179 hours and counting. Audiosurf comes in 2nd at 58 hours.

TF2 is about 175.  
 
Which is miniature compared to my WoW time. :P

TF2 over 900 hours now I think. And no idling.

Football Manager 2010 with 230 hours...
Football Manager 2011 is only at 111, for now.

Officially - 144 hours on TF2. Non-steam games don't seem to be tracked, so I'm not sure about SC2/WoW; but I rarely use Steam to launch those anyways.

Only 22 hours for Super Meat Boy.

GTA4 for 30-odd hours. Got so many new games on Steam, though, so I'd expect that will change soon.

I've played 274 hours of TF2 with no idling.

 Team Fortress 2 - 1265 hours
 
I really don't know how that happened especially since I don't idle...  

"  Team Fortress 2 - 1265 hours I really don't know how that happened especially since I don't idle...   "

300 hrs on TF2 
BC2 comes in second probably

" @Scrumdidlyumptious said:

"  Team Fortress 2 - 1265 hours I really don't know how that happened especially since I don't idle...   "

Oh my god. Are you a robot? "

People so quick to counter Idle claims ^__^ 
 
My TF2 is only a petty 74 hours without idle

Torchlight: 189 hours - super fun as long as you don't break the difficulty with mods. 
Second is Civilization V @ 86 hours.

70 in Empire.

Team Fortress 2- 167 hours.

155 Hours on Dragon Age: Origins. Thats like, two or three full playthroughs. 

I have over 250 hours on Team Fortress 2 alone, with Beat Hazard getting 87 hours and Garry's Mod taking up 60 hours on my STEAM account.

399 hours of Mount and Blade Warband
245 hours of Left 4 Dead
147 hours of Left 4 Dead 2
31 hours of Team Fortress 2
 
The rest are all minutes to couple hours or just unplayed.

Audiosurf at about 7.6 hours.
 
Super Meat Boy would easily overtake that if I had a controller to play with.

BC2 about 300h

Supposedly it's TF2 with ~100 hours

Of course this is lies, I've played way more TF2 than that (and probably over a thousand hours of CS:S- I never got very good in all that time), but I stopped playing regularly before they started tracking time. I think they started recording it in early '09?

" 399 hours of Mount and Blade Warband "

Probably Team Fortress Classic or Counter-Strike 1.6, but the hours I had played of those games in the past don't show so it's Deus Ex for 25 hours.

New Vegas, with a little less than 80 hours (79 and something).

Team Fortress 2 with 127 hours. Followed by Trackmania United with 100.1 hours.

Darksiders: 18 hours. /steamnewbie 
 
Playing through Alpha Protocol right now so think that might take over.

Garry's Mod - 42 Hours

I've spent 40 hours in Team Fortress 2, not bad considering I only bought it in June last year.

Civ IV, I'm embarassed to put the hours up here.

Resident Evil 5 with 26 hours (I bought it during the most recent winter sale). I have an S-Rank in RE5 again :)

Spectromancer, Dawn of War II and BFBC2. 

Team Fortress 2 ... 719 hours.  
 
Not the longest but quite interesting number is that I spend 22 hours playing Lara Croft and the Guardian of light ... did every challenge in the game + all achievements. 

My time has techinically been on the same game but I just been clicking a different Icon.
 378 hours on Dawn of war II and 291 hours on Chaos rising. With a whooping grand total of 669 hours or 27.9 days.
 I played well over 2000 matches and I'm super stoked for the expansion.