Of course we will want Sandstorm...
Otherwise pretty much anything that FIRST plays at the regionals or has already been listed in this thread.
But here are a few others that would be cool:
On
this page on Newgrounds Audio, the songs
Nightfall and
A Fast Trance Build. On
this page,
DDR Technotic Butterfly. (Sorry, but I can't figure out how to directly link to their songs. I know that these are free [and legal] to download.)