19. Shakira, 'Shakira'
Shakira's enough of a superstar that she has a bit more leeway than her peers — and she's talented enough to use that leeway toward unexpected ends. While the lead single from her 10th(!) album, the Rihanna-assisted "Can't Remember To Forget You," went the "duet with radio sure-thing" route, the record it led into had some thrilling twists and turns. The jittery, spare "You Don't Care About Me" gives an ominous edge to a relationship's lowest moments; while "Empire" turns the idea of the power ballad inside-out, its odd structure providing a grounding point for Shakira to raise her voice about the power of love. M.J.