18. "S&M" (2010)
"Sticks and stones may break my bones but chains and whips excite me," Rihanna sings cheerily on this Number One hit, featuring distorted and bouncy electro keyboard lines and lyrics written by Ester Dean. Arriving a little over a year after former boyfriend Chris Brown's vicious assault on her, "S&M" is a brave assertion of agency in the face of global public scrutiny. "People are going to talk about you, you can't stop that. You just have to be super-strong and know who you are so that stuff just bounces off," she told Spin that year. The overall theme? Rihanna does what she wants, and no one can stop her. "It's so good being bad," she coos. "There's no way I'm turning back."