Depends on my mood. Rock in general, but I also like classical, blues, jazz, Spanish guitar, and some pop, but rarely rap.
Favourites include:
Older rock: Queen, Cold Chisel, AC/DC, Talking Heads, Bruce Springsteen, Rolling Stones, The Doors, The Angels, INXS (early), Midnight Oil, Hoodoo Gurus, Beatles, Jimmy Barnes, Billy Joel, Black Sorrows, Creedence, U2, The Clash, The Corrs, David Bowie, Dire Straits, Elton John, Led Zeppelin, Pearl Jam, Guns'n'Roses, Red Hot Chili Peppers, Van Morrison.
Newer rock: Hedley, Faber Drive, Social Code, Arkells, Ben Harper, Jason Mraz, City and Colour, Butch Walker, Cold Play, Daughtry, Dave Matthews Band, The Decemberists, The Killers, Mumford & Sons, Neko Case, Paolo Nutini, Serena Ryder, Theory of a Deadman
Jazz: Miles Davis, John Coltrane, Harry Connick Jr
Country/Blues: Blue Rodeo, Carolyn Wonderland, Dixie Chicks, Johnny Cash
Blues: George Thorogood & The Destroyers, Chris Isaak, Gary Moore, John Lee Hooker, Ry Cooder
Spanish guitar: Rodrigo y Gabriela, John Williams
Pop: Black Eyed Peas, Beyonce, Dido, Missy Higgins, Norah Jones, Tristan Pettyman
Singer/song writers: Paul Kelly, Ben Lee, Bob Dylan, Jack Johnson, Joshua Kadison, Marc Cohen