Go to www.live365.com and search under the soundtracks section. There's about three, maybe four non-pay stations that play video game music 24/7. I'm looking to broadcast myself, just as soon as I have a three hour rotation.
For people in "The Uber Mainstream," using either AOL or Netscape, you can tune into Final Fantasy Radio. Kinda' nice, but the selection is kinda' scarce.