What's your most hours played in a video game?

[Adeptus Astartes]

On steam, I got 450 hrs in GTA V.

My most is probably Oblivion. Probably close to 1000hrs during my NEET post college era before I got a real job.

 

[SupaHotIce]

I probably spent more than 5k+ hours in Runescape and Sims 2, but I got 2.5k hours on Warframe