I'm pretty fond of David Wise's work. The easy pick is Donkey Kong Country 1 and 2 for the SNES, but he also worked on Iron sword: Wizards and Warriors II for the NES which has some great tracks too. Also the entire Battletoads and Snake Rattle n Roll soundtracks if I recall correctly (I was a Nintendo kid, if it isn't obvious).
If it isn't stretching too far forward, Einhander on the PS1. It's still the side scroller I judge others against and the soundtrack just feels "right" from start to finish.