Depends really on what mood i'm in, and where i'm driving , sometimes a nice bit of classical can be nice and relaxing if i'm stuck in traffic etc......
Otherwise 80's rock is preferred, whitesnake and def leppard work well along with all the other 70's & 80's rock suspects..lol.
if i'm out just for an early sunday morning drive then a some eagles goes down well as does some tubular bells , also some Chicane and Within Temptation (faster), don't listen to the radio much as I prefer my extensive cd collection instead.