Producer: Timbaland, Justin Timberlake, Nate "Danja" Hills
Album: Hard Candy

Next time you find yourself running out of energy while doing your last lap at the gym, do yourself a favor and play this 2008 tune. Not just because the beat sounds like a robot marching band is coming to install microchips in your brain, but because this track communicates the most underrated of all feelings: Urgency.

The song was supposed to be about saving the world, and based on pillow talk conversations JT and Madonna had. (Madge explained writing with Timberlake to Interview, saying, "Writing together with somebody is very intimate.")

Though all bets were off, JT definitely murdered Madonna on her own shit. Oh, and the whole saving the world thing? Blah. This song didn't save anything (peace to the ice caps!), but it was a hit throughout the globe, and charted at No. 1 in 21 countries. Insanul Ahmed