1D: This is Us

One Direction - Niall Horan, Zayn Malik, Liam Payne, Harry Styles and Louis Tomlinson - were discovered by Simon Cowell on the U.K.'s "The X Factor" in 2010. The band quickly gained a following to become one of the competition's all-time most popular acts, finishing in the final three and garnering a gigantic and loyal fanbase along the way. In March 2012, One Direction's debut album, "Up All Night," made U.S. history, as it was the first time a U.K. group's debut album entered the U.S. Billboard 200 chart at No. 1. The band has sold over 29 million records worldwide. In November 2012, One Direction released their sophomore album, "Take Me Home," which includes the No. 1 single, "Live While We're Young," and are currently on a sold-out world tour.