Toaster Hunter said:
Through the Fire and Flames
http://www.youtube.com/watch?v=9r3v3FkjznE
This.
But really you'll have to experiment yourself. Stick to music that you like but try to go for songs you don't know the words to. I find that if you don't know the words, it's just another instrument.
EDIT: Actually I'd recommend video game music, it's made to remain in the background but can still be energetic enough to influence you.