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.