I don't know whether I have a favourite style, but I love singer/songwriters, like Missy Higgins, Alicia Keys, the old Jewel and Kasey Chambers.
As far as bands go, I'd probably lean to emo/rock, Jimmy Eat World, Evanescence, Goo Goo Dolls, The Killers, Green Day, Jet, Eskimo Joe, APC.