What's your highest playtime in a game?

Counter-Strike:Source with 1475 hours.

Nothing on yours, but I have 750ish hours on TF2. It's just sort of built up over the years.

Killing Floor - 196 hours.

Actually I have tons more hours on Company Of Heroes but those were on my retail copy.

Not registered on steam, but it's the original Deus Ex.

CoD4, over 2k hours?

Well, I dont wanna know how much time I have spend with League of Legends, but with Super Meat Boy I have over 100 hours of play time.

Killing Floor - 181.3h

i had about 4k hours on counter strike condition zero on a older account,

dota 2, almost 500 hours

css with about 100hours

about 700hrs on TF2

AirRivals, tho doesn't register on Steam but Xfire instead.

Like 3k hours.

23.6 hours in Dota 2... Yeah I'm pretty new to Steam x.x

TF2 - 2000+

halo reach. way too much time but i love to play online. :D

1735h - Heroes of Newerth

1730h - Call of Duty 2

Sid Meier's Civilization V - 219.2 hrs on record

Back in primary school, i spent countless hours on Carmageddon 2, UT. Later on it was Morrowind. Every title over 2k hours.

97 hours on left 4 dead. but thats nothing compared to you guys :P

2400 hours ,TF2

World of Warcraft - 1128 hours

On Steam? Team Fotress 2 with 1,278.7 hrs

Anarchy Online 3512h on xFire, maybe a couple thousand more in total.
321 days 11 hours 52 minutes 32 seconds
24 days 3 hours 23 minutes 42 seconds
53 days 23 hours 1 minutes 2 seconds

Hmm: 399 days = 9576 hours. ~> 9,6k hours...

around 100 days + in cod4. good old days.

101.3 hours in Gmod