The tracked playtime is incomplete since the feature was added years after Steam launched. It's missing all of the data from 2003 to March of 2009. It also doesn't show offline playtime, which changes things quite a bit. CS 1.6 and Total War: Medieval 2 would top the charts by a long shot and TF2 would have plenty more too. Adding MMO's and games on other launchers would obviously also change things by quite a bit.

As for the tracked time on Steam:

Warhammer 40,000: Darktide - 585,5 hours
Tom Clancy's Rainbow Six Siege - 500,6 hours
Mount & Blade II: Bannerlord - 337,1 hours
Total War: Warhammer II - 306,4 hours
Total War: Warhammer - 305,3 hours
Team Fortress 2 - 293,8 hours
Deep Rock Galactic: Survivor - 289,3 hours
Total War: Empire - 246,9 hours
Palworld - 235,7 hours
Total War: Shogun 2 - 217,5 hours
Blood Bowl II - 179,6 hours
Total War: Rome II - 174,6 hours
Warhammer 40,000: Inquisitor - Martyr - 171,5 hours
Assassin's Creed Odyssey - 170,2 hours
Helldivers II - 140,7 hours
Baldur's Gate 3 - 128 hours
Pillars of Eternity - 122,1 hours
Cyberpunk 2077 - 121,8 hours
XCOM: Enemy Unknown - 120,3 hours
Mass Effect: Andromeda 120,3 hours

I've got several games in the 110-120 hours range, some of which I'm actively playing. Some on the list I'll be picking up later again to go through some new content that I just haven't had the time for yet.

Dauymn

Ark Survival Evolved → 5495h
Conan Exiles → 1781h
Dark and Light → 1087h
Dead by Daylight → 790h
Secret World → 470h
L4D2 → 450h
Destiny 2 → 443h
ETS2 → 310h
Skyrim → 307h
Cyberpunk → 269h

Neverwinter → 258h
Empyrion Galactic survival → 226h
Black desert → 219h
Marvel Rivals → 197h
Hogwards Legacy → 184h
Atlas → 137h
Survivang Mars → 137h
Trackmania Nations → 134h
Fishing planet (in another life) → 118h
Coloring Pixel → 115h

Social life ???

to scared to look, but anyway

20. red faction guerrilla re-mars-tered = 828.7 Hours
19. Crusader Kings 2 = 972.1 hours
18. Payday: the Heist = 1036.9 Hours
17. Fallout 4 = 1101.5 Hours
16. Grand Theft Auto IV: The Complete Edition = 1126.8 Hours
15. Call of Duty: Modern Warfare 3 (2011) multiplayer = 1199.1 Hours
14. Terraria = 1226.6 Hours
13. Payday 2 = 1323.4 Hours
12. Left 4 Dead = 1436.6 Hours
11. Call of Duty: Modern Warfare 2 (2009) Multiplayer = 1451.1 Hours
10. Grand Theft Auto V Legacy = 1513.6 Hours
09. Left 4 Dead 2 = 1541.2 Hours
08. Killing Floor = 1569.4 Hours
07. Garry's Mod = 1663.5 Hours
06. Killing Floor 2 = 1713.3 Hours
05. Counter Strike = 1789.4 Hours
04. Counter-Strike Source = 1854.5 Hours
03. Call of Duty 4 Modern Warfare (2007) = 1930.3 Hours
02. 7 Days to die = 2017.4 Hours
01. Counter Strike 2 = 2269 Hours

引用自 JacquesPatat：

to scared to look, but anyway

Seams we have the same social life

引用自 Mickey：

引用自 JacquesPatat：

to scared to look, but anyway

Seams we have the same social life :lunar2019grinningpig:

pretty much work, eat, game, sleep. rinse, repeat. But if i have to actually add, some more hours to three games which i had illegal copies of years ago before i bought it, then it would be good couple hundred hours extra

You can find the number of hours I’ve spent on my top 20 games if you know where to look, mr dataminer

Im ashamed of it don’t look

引用自 JacquesPatat：

引用自 Mickey：

Seams we have the same social life

pretty much work, eat, game, sleep. rinse, repeat. But if i have to actually add, some more hours to three games which i had illegal copies of years ago before i bought it, then it would be good couple hundred hours extra

I finished twice skyrim's story before bough it, and one run on Cyberpunk^^

1)Dota 2 - 6,861 hours
2)Warframe - 1,701.5 hours
3)Krita - 1,387.9 hours
4)Team Fortress 2 - 964.3 hours
5)Grim Dawn - 620.6 hours
6)Killing Floor - 603.5 hours
7) Counter strike 2 - 542 hours
8)Europa Universalis 4 - 540.3 hours
9)Left 4 dead - 495.5 hours
10)Crusader Kings 2 - 450.9 hours
11)7days to die - 437 hours
12)Dungeon Defenders - 394.1 hours
13)Warhammer 40,000: Dawn of War II - Retribution - 376.5 hours
14)Cookie Clicker - 353 hours
15)Titan Quest Anniversary Edition - 325.5 hours
16)Left 4 Dead 2 - 314 hours
17)The Elder Scrolls V: Skyrim - 299 hours
18)Divinity: Original Sin 2 - 281.5 hours
19)Terraria - 267.2 hours
20)The Elder Scrolls Online - 249 hours

Assassins creed odyssey 775 hours
Cyberpunk 2077 280 hours
Fallout 4 270 hours
Assassins Creed origins 40 hours
Yakuza 24 hours
Yakuza 2 40 hours
Yakuza zero 20 hours
Fallout 3 30 hours
Fallout new vegas 49 hours
Assassins creed shadows 62 hours (still in progress)
Doom 6 hours (still in progress)
I mostly played ac odyssey as you can see I just returned to steam recently with my legion go if someone can recommend me a good game please let me know

#1 Grim Clicker, total time played: 38877 hrs