Steam Most Game Hours on Steam?

For steam, Terraria (174 hrs.)
For elsewhere, osu! (209 hrs.)

GC Gmod 2000 hours. :D. I am good Coder Gmod

Counter-Strike: Global Offsenive, i've got 4.5 k hours at the moment, they'll keep going up a bit for sure!

6000+ HOURS ON CS 1.6 back in the day when steam wasnt there

Csgo and garrys mod,

Csgo : 2000 hours
Gmod : 1500 hours

I have 3000h on dota 2 (2500 on 1st acc and 500 on 2nd), 900h on GMOD.

I have 3800 hours on Garry's Mod and It's still not boring.

For me it would be Unturned though I haven't been playing in ages because it would always lag and crash on me.

Most Garry's Mod with 1000 hours and Counter Strike:GO with 500h hours.

i have arround 1900 on CSGO and 1800 on CSS xD, thats what i like :p