1
Serena Williams
The 34-year-old danced her heart out in Beyonce's "Sorry."
2
Rafael Nadal
There may never be a better shirtless cameo than the Spaniard in Shakira's "Gypsy."
3
Caroline Wozniacki
The Dane is no stranger to trying new things, and came out with her own single called "Oxygen."
4
Victoria Azarenka
The former No. 1 appeared in her then-boyfriend Redfoo's hit "Let's Get Ridiculous."
5
Mike and Bob Bryan
The musicians featured both Andy Murray and Novak Djokovic in their song "Autograph."
6
Serena Williams
The American showed off her singing chops with "I Will Survive" on The Tonight Show Starring Jimmy Fallon.
7
Gael Monfils
Martin Solveig's massive hit "Hello" also has appearances by Djokovic and Mathilde Johansson.
8
Justine Henin
After retiring, the Belgian showed up on a reality show called The 12 Labors of Justine Henin and sang "Now It's Time."
9
Vince Spadea
The American shared a little free-style rapping with the world.
10
Venus Williams
Wyclef Jean came out with "Venus (I'm Ready)" in honor of the great American champion.