I oscillate on the interstates. I don't go more than a couple miles at a steady rpm. My choices are (1) Accelerate (2) Go Faster (3) Slow Down as a Last Resort.

I prefer to listen to the growl of my 1200; just one of the reasons I don't ride at a steady pace.
I have listened to my Zune a couple times. When listening to LA Woman (Doors) I found myself crossing 110 mph during the jam at the end of the song. That song was made for a flat stretch in central Iowa.
Anything by Mark Knopfler gets me going fast(er). My favorite MK album for riding is Sailing to Philadelphia.
Get Yer Ya Ya's Out is a blast to ride to as well. That'd be an early 70's live album by The Greatest Rock and Roll Band in the World, The Rolling Stones. Street Fighting Man helps me get in touch with my Inner Aggressor.
My favorite sound remains the motor and wind.