Most hours spent on one game?

20000 hours spent on larry leisure suite ah good memories you should play too

6k hours on Warframe good feeling for grinding ninjas am i right?

Team Fortress 2 topping at 2200 Hours, though that was a while ago
CSGO at over 1500 and still slowly counting

i spent 4 hours in weekdays, and 6 hours more in weekend for Mobile Legend,
top global

After getting a VR headset I have sank another few hundred hours into Skyrim. Modded skyrim VR is amazing! highly recommend

Almost 2k hours in CS:GO, good knows how many in old non-steam 1.6

i have 1.2K hours on Arma 3

And i'm pretty sure i have 2K hours in Minecraft

I've spent over 1300 hours on Rust and on Minecraft at least 9000+...

Of all time, on both platforms I've played it on - most likely Rainbow Six: Siege - but according to Steam it's FiveM (Source SDK Base 2007) with a total 989 hours.

Back in the day this could easily have been 300+ but these days the content in games just isnt there to justify spending that much time. If we include things that have multiplayer like halo, the hours total would be over 9000 easily. lol