Some o' m' faves.
*Undertale* - Theoretically interesting, brilliantly intertwined cobweb of leitmotifs, complements each moment of the game beautifully, some fun Easter eggs for the musically inclined. IIRC, for a lot of scenes, the music was composed before anything else.
I'd single some out, but there's about a dozen equally top-tier tracks, some with leitmotif spoilers and some much better in context/at the in-game speed rather than OST (slightly different in some cases). Just play the game if you still haven't (fanbase-induced hype aversion sucks right?) and hear everything in context.
*Katamari Series* - What would Katamari be without its ingeniously eclectic soundtrack? NOTHING. IT WOULD BE NOTHING. Except a fun game with no soundtrack.
The Moon and the Prince -
https://www.youtube.com/watch?v=r2C8XvxYqos • Blue Orb -
https://www.youtube.com/watch?v=OK9pGJZWEkc • Katamarity -
https://www.youtube.com/watch?v=NoupxGlkYwk*PS1 Spyro trilogy* - Composed by the drummer for The Police, Stewart Copeland. Mystical and oddly idiosyncratic. Since I mentioned Undertale's music often came first, I happen to know the music in Spyro was built around each level.
Ice Cavern -
https://www.youtube.com/watch?v=7sbZZzDoSPo • Idol Springs/Fracture Hills -
https://www.youtube.com/watch?v=c6c-Toqnxgw • Bamboo Terrace -
https://www.youtube.com/watch?v=my6kw9WYb_w*The Legend of Dragoon* - Nostalgic JRPG music time. Great opening theme, everything else pretty great too.
Full OST in one video, timestamps in description, said opening theme is the final track -
https://www.youtube.com/watch?v=FzXuyzrMxow