Megaman 10. It's new. I haven't bought it yet, but I think the music is something of a masterpiece. Not in the same way that 2's or 9's music was though. It does something different. Slightly more ambient than I've ever heard from fully 8-bit songs.
So here's my stab at Chill Man. Can't wait to find a MIDI of Solar Man though! If you find one, let me know!