Apart from my other post, found this guy a while back. He (or she) extends the music from various video games such as Mario, Zelda, even Pac-Man. If you like video game music, he's your guy (or gal)!
Best of that is that you can get it for free at http://www.8bitpeoples.com/discography. They think that it attracts only a minor audience anyway, so why not make it available?