There's a visual novel game called VA-11 HALL-A. The soundtrack of this game feels more "organic" in some way, while it has a "cyberpunk" feels to it. I really enjoy the soundtrack, while the game itself were unique and interesting to follow.
Also... shout out to doseone for making this banger soundtrack for Sludge Life (prob one of the best Simulation Indie Game that i ever play this year)
im a sucker for thematics https://www.youtube.com/playlist?list=PL7peUsifFKgHEHnEsmIQMsa8l_0UqOyob
Super Mario Odyssey is another great soundtrack, though I don’t believe it’s on any streaming services.
I am a huge fan of Monster Hunter - I'd definitely call it my favourite game series - and the music is just one reason. Both old and new Monster Hunter games have brilliant soundtracks (for me, World took some getting used to, but that's just because it was so different from the other Monster Hunter games). Specifically, I think the third generation games - Tri, Portable 3rd and 3 Ultimate - have some incredible songs.
I'm probably a bit biased on this just because I love the series so much but I'd say it's worth mentioning either way.
Nothing compares to Super Mario Galaxy. It's amazing! Gusty Garden Galaxy is like Symphony No. 9 for Mario games! To The Gateway is such a sad song. But that is what makes it memorable. Just listen to it. If you need to be by yourself. Just go and listen to the ost.
Ori and the Blind Forest and Ori and the Will of the Wisps are in my Perspective the Games with one of the best Soundtracks ever
I'm amazed some of these haven't been mentioned yet:
The Choice - Gustavo Santaolalla (The Last of Us)
Nate's Theme - Greg Edmonson (Uncharted 1-3)
Mice on Venus - C418 (Minecraft)
Ezio's Family - Jespyr Kid (Assassin's Creed 2)
The Bannered Mare - Jeremy Soule (Skyrim, pretty much all music in that game is amazing but that's my personal favorite)
and just Cuphead in general honorable mentions to the 50's music in Fallout, Super Punch-Out music and The Elder Scrolls IV: Oblivion's main theme