I agree with those of you who picked Hotel California as a great song.
When I got my new MP3 deck and speakers, I started listening to all the old mp3s I had on disc. One of them was Hotel Cali, and when it came on, my GF and I sat in the car at 3 am just to listen to how fantastic it sounded, and that was in MP3 form!
For bass, I like Fat of the Land by Prodigy (firestarter and breathe, among others).
Metallica is good (and fuN!).
For clarity, get the remastered Kind of Blue by Miles Davis -- even if you don't like jazz, this is the one jazz album to have. Great music for relaxing or having sex. If you have sex in your car, you're one step closer.
Brian