I haven't seen anyone mentioning this gem:

Vampire Survivors

I can always go for a game of Age of Empires 2. That game takes me back to my childhood.

Euro Truck Simulator/American Truck Simulator

It quickly just becomes a virtual road trip simulator, and as someone who generally enjoys driving and road trips its very chill

Deus Ex, Vampire: The Masquerade: Bloodlines, and Cyberpunk 2077. Like you said, they are games I like to get lost in, just walk/drive around in, soak in the ambience. I like to pretend I'm there; it's a great escape, like you said, comforting.

I have a few, Skyrim is my biggest one. I basically maladaptive daydream Skyrim. If I'm feeling bad I play through it in my head. Some others are No Mans Sky, Vampire Survivors, and generally pixel games are always really comforting to me. I also like to go back and play dragon fable sometimes when I need some nostalgia.

Morrowind and Mario Maker 2.

Oddly enough I go through phases where I just level up a character on WoW. It's mindless for me and I can just zone out and watch TV while playing.

Star Wars: Racer - I know every track by heart at this point, have it on my Switch and still play quite a bit. Amazing flow state game.

Rollercoaster Tycoon 2 - absolute classic and the nostalgia I get from playing is unmatched

Age of Empires 2 - the music is just muah

KotoR - Best Star Wars game ever made next to Dark Forces 2 and Jedi Outcast

I could (and have) spent hours in Valhiem just noodling around surviving as a Viking

It has been a while, but there was a time when, if I was feeling really anxious and almost panicky, a quick playthrough of Enter the Gungeon would chill me right out.

Chrono Trigger. Always feels like being home with old friends. A joy every time I playthrough

Unraveled (Unraveled 2 is great for 2 players, too), and Hue. Then there's always Slayaway Camp. All good on Steam Deck as well.

But those are for the times when I'm not addicted to RL.

Minecraft. It's just a nice game to get lost in.

No Man's Sky is a good mix of nice scenery, low stress, and engaging without requiring a lot of mental capacity that can be comforting.

TES Oblivion and Sonic Adventure 2. SA2 was a childhood favorite I got very good at, and the extra mission, game modes, and pet sim aspects makes it fairly re-playable without having to start a new game file. Oblivion is just whacky and fun, and if you know how to exploit mechanics you can get up to some pretty crazy stuff in a matter a minutes after starting the game. While grinding skills could be seen as... Well a grind, it's a grind I personally enjoy. Both games let me dive straight into what I'm feeling like doing, and reward mastery (even if one of them is cheese mastery).

Try not to have an overly rosy retrospection about this. There were plenty of crappy, cash-grabby games in decades past. We just don't remember them because they were crappy, cash-grabby, and not worth remembering. They hadn't invented microtransactions yet, but that's just one more flavor of crappiness.

Easily Path of Exile. There's something so relaxing about blowing up the entire screen with one flick of my wrist, and it really gets my endorphins flowing to minmax my stats using third party tools like Path of Building and testing out items on the trade site / changes to my skill tree to see how they'd affect my build.

To some people it sounds like work, but for me it hits that sweet spot of minmaxing and complexity that no other game really can.

Edit: I should also mention that lately I've been mostly playing on Steam Deck which has been a revelation for me. Endgame "alch and go" mapping is so perfect for the pick up and play style, only enhanced by having access to it from the couch/toilet.

XCOM 2 on the lowest difficulty. Sacrilege, I know, but there's just no better feeling than waltzing through some aliens with my whole squad intact at the end while feeling like a tactical genius. And even the weird Chimera Squad is just fun at times for a bit of a changeup.

I always find myself coming back to Monster Hunter every time I wanna chill and relax.

Elite Dangerous in VR. I can really disconnect from the real world and just enjoy being a space-pirate bounty hunter.

super Mario galaxy for sure

When I was very young I had something wrong with my nose and I couldn’t breathe so I had to get surgery

When I left the hospital my parents said I could get a game to play while I couldn’t go to school for a week and I chose super Mario galaxy

I played the shit out of that game and it just has such a calming positive vibe, like everything is gonna be ok

That game is a part of me, I love it so much

… that or left 4 dead 2

lately: against the storm. making a city builder into a roguelite was genius.

Portal. I've played through it enough times that I can complete it in a little under 20 minutes. I'm not very good at games but there are a lot of fun and easy tricks to run through it quickly. Playing it a bunch of times is relaxing and fun for me.

For me, it’s always Ocarina of Time. The music always improves my mood and there is something oddly comforting about the game.

Anyone of my simulation/management games. Whether it's running a hospital, creating an auto manufacturing assembly line or helping some brave adventurers find oxygen I'm always more at peace with a single player goal driven experience.

Stardew Valley is amazing for this. Minecraft was it for years and years, but Stardew is just like a nice hug. I adore it.

Hogwarts Legacy has also fallen into this category for me now.

Stardew Valley is my go-to. I found Firewatch really easy to get lost in too.

Stardew Valley comes to mind right away, but I think it applies to all titles after you get the hang of it, with the exception of heavily RNG-based games like Risk of Rain 2, Hades, Dead Cells where you have to be alert almost all the time. Currently I'm enjoying playing Red Dead Redemption 2. Definitely a comfort game just riding your horse around.

MH Rise (Lance for tank mode) - fighting Melvor - idling Disney Dreamlight Valley - collecting Hardspace Shipbreaker - dismantling

For me it's No Mans Sky. I love flying around and checking different planets, it's kind of calming for me.

BOTW for sure. The expansive open world is just great to get lost in. Not to mention the soundtrack can be calming when you're out riding your horse in the fields.