I mean, I would say Overwatch 2, but... I have yet to successfully quit that game.

I see Dwarf Fortress mentioned. I’ve played ridiculous amounts of time, it’s one of my favourite games of all time, but I don’t think it had any major negative impacts on my life other than a few tired nights (along with games like SimCity 2000, SimEarth, and even SimAnt, strategy games like Star Craft Brood War, Victoria 2, Crusader Kings 2, and Sid Meier’s Civ 2).

Dwarf Fortress isn’t just a colony sim, it is so much more than that: a dynasty simulator, a history simulator, and Empire building game, a cultural simulator, a war simulator, an environmental simulator, and an emergent storyteller, and so much more. It is one of my favourite games of all time.

Yep.  And I would add Witcher 3, just now playing it for the first time.  All 3 of these games just make time fly.  

Yakukza: Like a Dragon. I played it everyday; all day into the late night.

Wow some of your hours played are crazy. If anything mine would be Phantasy Dtar Online in Dreamcast/Gamecube

Phantasy Star online episode 1 and 2 in Gamecube.
I only play offline, and i play more than 1500 hours in that game.

Team Fortress 2
I got well over 2k hours on it AND I CANNOT STOP PLAYING IT, every damn time i try to quit it, my mind keeps on telling that i should play some TF2, like WTF???