Not sure if I have a superb example... Dunno if they use nes-trackers (which undoubtedly give the coolest sound) but I know some using the most out of the 8 bit powers of the 80s. Hehe.
HORSE The Band - Murder, or all of them in general have 8 bit sounds in them.
Then you have Machinae Supremacy. They make what they call SID Metal. SID is the sound engine in the old Commodore 64.
Death From Above
Winterstorm
Gimme More (SID). Yes, that's a Britney Spears cover.
The Overworld album in general has a lotta modern synths and stuff and less 8 bit stuff in it, but all in all I guess you can get an idea of how they've used it as an addon to their music.
When I said nes tracker I guess 8 bit is all good enough, but I have a deeper love to nes tracking and the distinct Nntendo sound. And for that I can only give examples from Nintendo games I guess. Allthough there are some who make nes chiptunes for fun too.