I listen to a range of things from Hardcore, House, Trance, Dnb, Techno and sometimes some of the old skool stuff! I think house works best for me though!
Deathcore - Suicide Silence, Whitechapel, Veil of Maya, All Shall Perish, Born of Osiris, Bring Me The Horizon, Opeth) Metal - Children of Bodom, Slipknot, Machine Head, Metallica, KoRn, Mushroomhead, Seether)
That's about it while hacking. :P I like my music upbeat and loud to keep me focused. :P