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.
Rye Umemoto is a legendary composer who worked on a large library of Japan-only PC games in the 90s, in particular, NEC PC-98 computers.
The PC-98 used a slightly more advanced but older FM synthesizer soundchip that was a relative of the one SEGA used in the Genesis. The Genesis had the YM2612 and the PC-98 had the YM2608.
His work on Xenon, Desire, YU-NO, EVE Burst Error, Grounseed, etc were just fire. I think his works were the best during that era. I havent found a single one of his songs to be subpar. He definitely knew a good song fit the mood of the game, and didn’t only have fancy arpeggios.
Grounseed - Morning
Desire - Ishtal
YU-NO - Intro
Grounseed - Real. Life
EVE Burst Error - Room (Marina)