Hells yeah, I love Madonna. +1 on the love for Human Nature. That song is incredible when you consider it's from, what? 1993? And it's basically a screw you to anyone trying to put a damper on her sexuality and sense of self because she is female. But the message works for anyone being held down, and is still necessary considering how many people are still hung up on those issues.
My all time favorite is "Like a Prayer".