I usually play a mix of ska, punk, power metal, and other junk.
My favorite artists include:
Ska: The mighty mighty bosstones, the planet smashers, deals gone bad, mustard plug, the skatalites, the toasters
Punk: anti-flag, pennywise, bad religion, the vandals, mxpx, blaster and the rocketman, minor threat, gorilla biscuits, youth of today, judge, ss decontrol
Metal: amon amarth, kamelot, finntroll, ensiferium, hammerfall,
Everything else: Everclear, blink-182, relient k, krs-one, sage francis, ytcracker, mc frontalot, shafer the darklord, mc lars, zealous1, madhatter, dr. dre, doug e. fresh