There are some pretty famous bands from Athens. The B-52s, R.E.M., Of Montreal, Neutral Milk Hotel. There are plenty of other good ones, too.

One of my favorites, that I've seen live, is Cinemechanica. They play some live shows under the names "Mega Band" and "Contraband" where they play Mega Man or Contra on a big screen and perform a rock rendition of the soundtrack. Kickass stuff.