I think the reason I like Genesis audio so much is because it was sort of the final hurrah for chiptune style music, in so much as the 16 bit era was really the last time each console had an individual sound. For obvious reasons everything went the SNES route after that and started using samples or prerecorded soundtracks.
But yeah, it depends on the game I guess. FM synthesis is a bitch to work with and can sound really grating if you're not careful. When used properly though it's amazing: