A few from my collection:

Acts of Creation by Kathy Mar (it must be online somewhere because I downloaded it once, but I can't find it now)

Make them Hear You from Ragtime (probably most effective within its context -- the character singing is about to walk out to face near-certain death)

Fins of Human Knowledge by Ben Newman

I'll second everything on http://www.prometheus-music.com/space.html

And if Brighter than Today ever gets recorded, please post it here.