I'm a nineties brat, so I still listen to a lot of that; Pearl Jam, Alice in Chains, Machines of Loving Grace, Nirvana, Tori Amos, that sort of thing. I'm also something of a goth chick, so I have a lot of VNV Nation, Wolfshiem, Wumpscut, the more industrial-sounding music.
I like GOOD house music too, not the plinky rave stuff, but if it's nice and solid and has a good harmony to it I like it.
Also something of a lyrics nerd. If it has good lyrics, really good lyrics, I'll like it no matter how the song is sung. For that reason I like Counting Crows. ^^
I'm not real big on rap, aside from DMX and some Busta. HATE country music. I can't listen to it.
Other than that just about anything goes. I even like some madrigals and medieval choir arrangements, in particular the Miserere Dei, I can listen to that over and over.
So just about everything, other than country and most rap/R&B.