I have too much of a collection to get specific on bands.
Sirius radio + 80 gig iPod in the car. Very varied tastes, mostly classic rock, hard rock, alt rock, metal, but sometimes a little blues or hippie coffe-house music.
I listen to the same stations as YF19pilot (minus Nascar, I don't care for it). Usually I throw my iPod on shuffle.
The best driving music is Any Old Metallica, first four albums -- your heart will race and your eyes will be popping out of your head. I also like old Van Halen for cruising around with the wife. But usually I have my iPod on shuffle and I get something random in my vast collection.