I love these games and I think the soundtracks are underrated as an essential part of their appeal. I’ll Start with one:
https://www.youtube.com/watch?v=Kk72RMv9d0s
Tube of Medusa from Ecco2: Tides of Time.
Personally, I think the Sega CD version soundtrack is… fine, but it has a different composer. If I remember correctly, it;s the composer from the first Ecco. In my opinion, it’s inoffensive, but completely forgettable.
EDIT: I have edited the topic to include older stuff.
The mainline Nintendo games all seem to have incredibly memorable sounds. Just earworms from start to finish. Yoshi’s Island, being late on the SNES, has a unique sound.