Because Ari did it first, and then I added on to the list of songs that are good for playing DMC3 (especially boss battles) to. Re-uploaded her's, because the link's probably dead by now, and added my two, which come care of my brother.

MDFMK - Witch Hunt
Lightning Bolt - Dracula Mountain
Lightning Bolt - 2 Towers

The Lightning Bolt stuff is definately background music-ish - you'll probably be bored if you just sit there listening to it, but it's great for playing video games to. I generally put these three on a playlist, and just hook it up to the speakers instead of the PS2.