Count down the top 10 hits below on Billboard’s Top Hot 100 Songs of the 21st Century retrospective, and check out the entire 100-position chart in Billboard’s Greatest of All Time charts menu.

Fifteen years into her Billboard ... 100. Elsewhere, 50 Cent boasts four entries in the top 20; Carrie Underwood places with her American Idol coronation ballad, “Inside Your Heaven”; and hits ...