I didn't see anyone who mentioned this one but what about the Descent 2 redbook soundtrack that came with the CD? There are likely other tracks that may be enjoyed but the CD music is by far the best!
Here is a forum topic with all the soundtracks from both Descent 1 and Descent 2, but I think you would enjoy the CD tracks the most. http://www.planetdescent.net/index.php?topic=1255.0