I don't do a lot of programming, and I ain't done any for Civ yet, but when I am programming a robot or modeling something, I usually listen to progressive rock like Dream Theater, Anathema, or Nightwish. If it's near Christmas, I've usually got Trans-Siberian Orchestra on, and right now, I'm listening to thei precursor - Savatage.
Also, I have recently discovered some opera that is fairly enjoyable - Roger Water's (from Pink Floyd) "Ca Ira" - and then I always love to fall back on classical giants such as Bach, Beethoven, Chopin, Pachelbel and Tchaikovsky.
I also always enjoy listening to movie scores. John Williams, Hans Zimmer, Klaus Badelt, etc.