Driving is practically the only time I listen to metal these days. Part of this is because I prefer to play it loud, and I try to avoid annoying my neighbors with loud music when I'm at the apartment. Additionally though, metal is very physical music to me, and I feel a need to be outdoors and/or doing something when I hear it. It's just not the same when I'm sitting on my ass in front of the computer.
That said, pretty much any genre goes when I'm in the car. It just depends on my mood and/or the driving environment.