Steam

Quake Champions and Monster Hunter Rise

Oxygen Not Included and Baldur's Gate 3 for the 1 month out of the year I take a break from ONI.

Tough question. I'd say Stellaris and Neverwinter Nights.

Stellaris is giant with so many options, it would take a while to get stale.

Neverwinter Nights has hundreds of homebrew campaigns available, and with the PRC mod also hundreds of classes & races to play.

Monster hunter world and satisfactory

Killing floor and chivalry. It'd be like Valhalla.

Civilization 5 and Space Engineers

Just woke up. I thought this was a picture of valheim with a deathsquito on the background. Which is interesting because I was probably going to have to pick Valheim and Sims 4. If I can only playb2 games forever I need sometimes that doesn't necessarily have a main quest then it's done and both of those fit that.

Path of Exile for sure, not sure about the second though. Maybe Dark Souls 2, Elden Ring, or maybe XCom 2.

CS2 & super auto pets

Rain World!!!!!
Second place is hard to do though! Oxygen Not Included, I guess?

Valheim and Starfield.

Apex and Rimworld

Dota and Baldur's Gate 3.

I've been playing Dota since it was a Warcraft 3 map...

And Baldur's Gate 3, I don't know if I've ever done a second playthrough of any RPG I've ever owned before. Most of them I usually get bored and quit before the end because it's like... I get it... But Boulder Gate 3 I've beaten three times so far currently working on a fourth run which is an honor run. And I've been making a list of mods that I want to try to make.

Grim Dawn* and Rat Party.

Dark Souls 2 SOTFS, Borderlands 2

Satisfactory and Titan Quest

Arma 3 and GTA VI

No Man's Sky and Light No Fire

That is a hard choice

Stellaris is number one and Skyrim or Fallout 4 for number to just based off mods available.

… what is steam? 👀