The Dillinger Escape Plan
Anyone listen to these math metal \ grind/jazz -core geniuses? There's no-one quite like them. Their best work is the EP "Irony Is a Dead Scene" where they have all-things-music uber-mensch Mike Patton as vocalist. That's probably the best EP ever released, period.
Be 100% sure to check out their song "When Good Dogs Do Bad Things". Don't miss it...don't!