Video: Avril Lavigne [ft. Lil Mama]: "Girlfriend (remix)"
As if the slick, snide surge of Avril's "Girlfriend" wasn't enough bliss, "Lipgloss"-wearing teen scream Lil' Mama had to go and put her thing all over it. Avril's ode to boystealing falls back while Lil' Mama "deliver[s] them lyrics than people focus on," and the two pal around like they've known each other since grade one. Best moment: when Lil' Mama jumps back on the track to ask "please, 8 bars and stop?" Second best: Mama following Avril's "I don't like your girlfriend" with a definitive "nope." Third best: everything else.