Avril Lavigne is pop's presiding mean girl, sneering and snarling like a punk kewpie doll with Tourette's over some of the most sticky-sweet melodies ever to hit the Billboard charts. "What the Hell" is Avril in a nutshell: Co-written by Max Martin, it's an anthem about a good girl who goes on a crazy-bender, staying out late, swapping boys and exacting psychological revenge. She starts out defiant ("All I want is to mess around") and quickly turns vicious: "I am messing with your head/When I'm messing with you in bed." (In fairness, the dude has been pretty neglectful.) The music is easily some of Avril's catchiest yet, with piping garage-rock organs, a pogoing, do-the-frug beat and a soaring singalong chorus. It's strychnine disguised as bubblegum.