http://www.mickstjohn.net/music/
It's got songs that aren't available anywhere else that I know of. It's divided into sections: one for each episode, plus one for the unaired pilot, and one for the promos. You can listen to Moonlight songs for hours!

If you're not familiar with the website, the main page is http://www.mickstjohn.net -- a "professional website" for Mick St. John. Don't forget to click on the "Map" tab, too--that's where the Moonlight Locations map is located, including a downloadable Moonlight Guide in PDF format (both high and low resolution).