45. M.I.A., 'Born Free'
Given that M.I.A. sampled the Clash on her breakthrough single, “Paper Planes,” it’s tempting to call “Born Free” her “London Calling” moment. But really, it’s more akin to the Beastie Boys’ “Sabotage,” a hip-hop spin on punk rock, cribbing from an old Suicide song (“Ghost Rider”) for its fuzzed-out, guitar-like synths and thundering backbeat. And like "Sabotage" before it, it flat-out rocks.