Hey Ben, in April 2007, there was this post on Joystiq announcing 2 free chiptunes albums. I just went back in time and found it.
Go here: http://www.yarhalla.jpn.org/yarhalla/16d/index_e.html
The 2 albums are Go Square and Gone Square and they're both by Dong. They're both pretty rad.
If nobody else is going to recommend something, I guess I'll just download something randomly from that same site and hope it's good.