I listen to very different music when I am working out than I would normally. It's my time to give in to those guilty pleasures.
#1 Fav for workout - every time I use my iPod, I start with this song:
I Run for Hope - Melissa Ethridge
Others I like:
Glamorous - Fergie
Fergalicious - Fergie
Survivor - Destiny's Child
Independent Woman - Destiny's Child
Stupid Girls - Pink
U + Ur Hand - Pink
Run, Baby Run - Cheryl Crow
Lose Yourself - Eminem
Stronger - Kanye West
Welcome to the Jungle - GNR
Pour Some Sugar on Me - Def Leopard
Sexy Back - Justin Timberlake
Soulja Boy - not sure?
Machinehead - Bush
I like this thread! I am sure there are tons more songs that I would like to workout to. As many of you can probably relate, I don't really listen to the music that I grew up with anymore. Kids, work, school all seemed to have gotten in the way. Here's to re-discovering that part of ourselves!

Hairbrush song is great...I also love the waterbuffalo song!
I am loving the honesty of the guilty pleasure music! I am right there with you! Whatever gets us movin' and groovin' right? Too funny!