Alternative Rock, often with a bit of Progressive rock, Symphonic Rock or Psychadellic Rock thrown in. That's my favourite but I like most genres of music except Pop, Dance, R 'n' B Hip Hop and Rap. The only rappers I listen to are Run DMC, Rage Against The Machine and the Lonely Island. I can stand Eminem, but only barely.
When I say Alt. Rock is my favourite I'm talking about New Prog and the like (Muse, Porcupine Tree, Blue October, Biffy Clyro etc.). I don't mean bands like Paramore and Panic at the disco whom if I listen to for more than 10 seconds I am forced to gouge my ears out with whatever implement I may have on my body whether it be a pen, a spoon or a boltgun.