I'll listen to most music - had Radio 3 on all day today because it's just been full on awesome. I do love a bit of proper early music - which is generally classed as 12th-17th century... polyphonic plainsong transports me! Saying that, I like anything metal turned up to 11, and rock the 80's every no and again. I even like some modern stuff.
The best music though? Music that I've made myself, whether it's completely improvised rubbish, or making music out of the dots some else has written down. That's where the best music is