At work I'm limited to listening to the fans of the 30+ machines near my station. Occasionly there's a machine behind me that starts freaking out, but I can't quite call it music...

Then I have the soundtrack that I play in my head, I seem to play a lot of Blue Öyster Cult, especially Career of Evil. Though Nine Inch Nails, Neil Diamond, Abba, AC-DC, Liz Phair, and several others crowd in occasionly. Now that the car stereo is fixed, maybe it will settle into whatever I listen to on the way to work.

At home, I've got a random list of 4000 MP3s that I listen to that are mixed in with samples from Daily Wave

Update: And most of those MP3s were self ripped at 160, though I'm starting to use OGG Vorbis now.