I like pretty much anything that's good, but I'm not much a fan of hip-hop or rap (unless it's older stuff: LL Cool J, Run DMC, Whodini, etc).
My favorites tend to be 80s music, alternative, grunge, hard rock and metal. But again, I listen to just about anything if I think it's good. If you look through my music collection you'll see all kinds of stuff from Henry Rollins to Kelly Clarkson, Metallica to Goo Goo Dolls, Primus to Fergie, Alice in Chains to Grandmaster Flash...all kinds of stuff.