I’d have to go with Flatout 2. Incredible game, incredible rock and metal tracks.
I like Undertale
Morrowind and Arcanum are the first things that come to mind.
Halo 1, Minecraft, Runescape, and Splinter Cell Chaos Theory.
Nier is my go to slug answer. Incredibly unique sound, but I have been playing through the visual novel Fata Morgana rn and it has a similar kind of aesthetic and it kicks ass. Utterly fantastic tone https://www.youtube.com/watch?v=uAbauJc4Oxo. My other go to answer of course would be SotC and its very funny listening to it by itself that’s obviously composed by somebody who composed for Gundam. Another vn I don’t really like but I do think is a very interesting playthrough and has a few great emotional tracks as well https://www.youtube.com/watch?v=bZWd_7Ud-Lc
Every single FFXIV track
World of Warcraft has the iconic ambiance music
Pillars of Eternity 1 & 2
Divinity Original Sin 2
Tyranny
Bloodborne
Darks Souls 1-3 - I write to Gwyn’s music on occasion and the Majula theme from DS 2 acts as a muse for all my writing sessions
Neverwinter Nights 1
Bastion
Donkey Kong - Every single fucking song rocks