Asklemmy

Either skyrim or oblivion. probably Oblivion. It's the most immersive game world I've encountered. Emminently replayable.

Easily 10k hours throughout the Diablo series.

Over 750 hours in Total War: Warhammer II.

Probably 2,000 or so in Guild Wars 2.

Gtav on ps3 was a blast.

I have 1000+ hours in Forza Horizon 4 & 5, mainly due to weekly FOMO (new car every Thursday).

~800 hours into PAYDAY 2

~1800 hours in various sim racing games, assetto corsa, project cars 2, dirt rally/DR2, rFactor2.

And some ~300 hours in Stationeers

Haven't checked in a while but I think my personal record is 1400+ hrs in Europa Universalis IV.

Path of Exile. It literally captures you once you take a grasp on game mechanics and find an interesting character build.

Oh boy, theres a lot to talk about chatacter building.

Theres no ARPG game in the market with such complexity in planning your character. Dopamine hits when you reach your build's peak and while you chase for milestones, like upgrading gear, leveling, bossing, etc. Leagues are breath of fresh air, introducing expansions + new content, also possibility to start a fresh character in fresh ladder & economy.

Playing PoE with pals in a guild and sharing milestones, moments, items & currency, helping each other with progression sucks you even further in.

Its so addictive that I've had to stop playing it, because it takes so much of your time. But I don't regret playing it. Good times.

EverQuest 1. Diablo 1,2,and 3. Cities skylines. Forgot about terraria.

Breath of the Wild. I put about 300 hours into it.

World of warcraft. Still true. I only played up through Crusade even. But it ate literally dozens of days of my life. I wouldn't say I regret that, as it was a learning experience for me. But I would definitely not have played wow if I could go back.

Continuum. I have more than 10 thousand hours on my main account, 3 thousand more on alts I do not have access anymore. Most of the time was afk or just being online since it had a chat and very lightweight. You can see top players by usage time on the trenchwars server website.

Microsoft flight simulator thanks to slow internet and 200gb updates every time I play.

Stellaris almost 600 hours and Cities Skylines, around 400 h. Damn!

Looking at 600+ hours in Rimworld, and probably even more in Dwarf Fortress but 200+ since the Steam release, it wasn't tracked before.

That would be Elden Ring. Spent 200+ hours on that game (might sound like rookie numbers but that was my first open world game, was just a casual gamer before that).

hotline Miami, katana zero, ultra kill.

Crudader Kings 2 at 1400 hours and Total War Warhammer II and I at 800 hours

Minecraft. 2.5 kilo hours

Diablo 2 from launch, I won't even guess the hours because it's over 10k easy and that's just not good. Path of Exile says 4k+ hours as well. I'm an old fart though.

AI (Alien Isolation)

Dunno if counts as a game really.. But about 4k hrs of VRChat - love the place and the friends I made there!

not really a single game but probably accumulated the most hours playing Super Mario World kaizo romhacks

single game would probably be Battlefield 4 though

Guildwars2, 14000+ hours. Mostly WvW.

Probably GTA Vice City back in the day. So much room to just dick around and kill random people.