What game have you played for the most amount of hours?

[KoiIroRazu]

Dota 2: 2.342 hrs
TF2: 1.190 hrs
CS:GO: 608 hrs
Tales of Symphonia: 500+ hrs
osu!: 450+ hrs
Touhou 6: 200+ hrs
Star Fox 64: 200+ hrs

Those are the ones I can think of right now. I also put a lot of time in OoT but I can't really guess how much.