My tastes tend to be somewhat eclectic, but it's mostly electronic stuff. I have an old, outdated cd list out somewhere...
http://www.intrasound.com/robert/cd.html
My wife thinks it's all abstract beeps and blips. She gets me though and sneaks Britney or the like onto my shuffle. What a surprise that is at the gym - really bad when I start getting into the song before realizing what it is.