I'll answer a little for both Shuugo and myself: Kajiura Yuki.

The follwoing is just for myself:
My taste in music is pretty broad. I'm just not in for "hard" rap, mainly because the lyrics tend to suck and I hear enough bitching about life from myself. Don't need to hear how someone making money selling their (lyrical) bitching thinks their life's sucks...

Oh, that and I tend to get the sense that the rapper has something stuffed in his mouth preventing him from enunciating words properly...(Why bother with real lyrics at all if you're gona pronounce them incomprehensibly anyway?)