My favorite song: VII by Akiko Shikata. It has almost no repetition, both a slow and fast melody, and manages to be both creepy and epic at the same time. Takes a while to speed up, though. Not really sure what genre it falls under, though.

I'm also pretty into the NieR Gestalt soundtrack right now. My favorite from the Album is the Shadowlord {White-note remix}; a piano and choral song. Didn't really like it first, and the beginning is a little slow, but it really picks up after 1:24.

Other than that, I have some piano songs, some music from anime, some classical, some symphony, and a couple others. Only have a hundred songs on my library, and I'm pretty picky with what music goes on there. I don't dislike any particular genre, but I usually dislike repetitive songs or slow songs. I also prefer female vocalists ;)