Sum 41

This is the record where Sum 41 realized they didn't have to be Green Day anymore and began to forge their own pop-punk hybrid, sticking to the winning formula of "Fat Lip" from All Killer No Filler, where they paid their abeyance to their love of metal in an unexpected rap. There's more rapping, more metal and more frenetic playing that you can't ignore. The guitar riffs are anxious and jittery, the harmonies claustrophobic and the tone sometimes heavy and ponderous, like on the standout "Mr. Amsterdam." But this band took a giant step toward the future of punk in just 31 short minutes.