For driving (other tasks require different music):

3.5L Isuzu V-6 coupled with a TOD 4L30E transmission.

I just like to listen to my engine most days. I've saved my own *** more times than I can count by hearing changes in road conditions or engine performance.

But when I'm out for something to keep me awake:

Carl Orff: Carmina Burana
Gustav Mahler: 5th symphony (Chicago w/ Solti) ... Mahler 5 rules for destroying sound systems (quiet, quiet, quiet .... fff full orchestra)
JS Bach: anything .. fugues RULE!
Metallica: Ride the Lightning (their finest work IMO)
Brian Setzer: Jump Jive and Wail
Rammstein: Rammstein
Mortal Kombat soundtrack
The Matrix soundtrack
Nobuo Uematsu: Final Fantasy 1-11 soundtracks
NPR - whatever's on ... starting to have too many commercials (stupid sponsor announcements and fund drives amount to commercials without the cheese)

Also, whatever else I grab on the way out of the house ... a lot of stuff I like I don't even have on CD, especially Jazz and orchestral music. XM radio is looking awful attractive.

So, in order my genres are: automobile sounds, orchestra/classical, trombone misc., Jazz, heavy metal.

I listen mainly to various electronica and game music stations on Shoutcast at work. They tend to fade into the background of my conciousness and not distract me from what I'm working on.