Help me broaden my workout mix horizons:?

I have an ipod that I love to death and use to mainly bike with (run if my foot agrees). I listen to alot of Metallica S&M, Pink Floyd, a little Green Day, and even the 1812 Overture to make my workout right, but unfortunately I only have about 60 songs in my workout playlist so I’m starting to get tired of some of the selections-even though they are great songs.

I used to have a hard drive with tons of great stuff I love, but I lost it last year…I need suggestions of something that’s going to help me get up and GO!

I will try most anything you suggest that I don’t already have knowledge that it otherwise doesn’t meet my taste…I also go heavy on the GA button for good stuff.