Gonna have to go again with DoDonPachi. It might as well just be it's own fucking radio station. It has so many damn soundtracks that have penetrated so many genres including rock, trance, techno, chiptune, dupstep, and even jazz at some points. But DoDonPachi 4 Black Label...my favorite.
Then comes Mirror's Edge and the Solar Fields score. That was some euphoric goodness.
I hear Castlevania come up often. The music is very iconic, but I'm certainly not a fan. Maybe I should give it another shot, though -- I don't listen to it very often.
I'm gunna start right now: Every Katamari game.