8bitpeoples (http://www.8bitpeoples.com/discography_gfx.php) Has a bunch of MP3's of music made with Game Boy, NES, etc... Lotsa trance kinda stuff and there is a Christmas cd on here, too.
If you get into "chiphop" you can also get your chip-on at The Internet Archive:
http://www.archive.org/details/PhlogistonPhlogistonvsSpamtronTheAnimalKingdomProbablyWouldntExistWithoutWasabi (http://www.archive.org/details/PhlogistonPhlogistonvsSpamtronTheAnimalKingdomProbablyWouldntExistWithoutWasabi)
This was a chip-hop battle, but if you keyword from here you can find wuite a bit of, well, 8bit.
I clicked the links , but I had no clue what I was reading .. it was going over my head. . :(