Who: Sarah Silverman, actress and executive producer, “The Sarah Silverman Program”

Why: Ms. Silverman’s star skyrocketed this past year thanks to the combination of sex and celebrity. Ms. Silverman’s Emmy-winning “I’m F***ing Matt Damon” video, which musically documented her faux affair with the “Ocean’s Eleven” star, aired first on “Jimmy Kimmel Live” Jan. 31 and spread quickly across the Internet, racking up tens of millions of views around the world and spawning several parody videos—and a musical response from boyfriend Jimmy Kimmel, “I’m F***ing Ben Affleck.”

The success of the video helped lift the second half of the second season of her Comedy Central series to record viewership. She also gained attention in the political arena this year, lending her talents to “The Great Schlep,” an online movement sponsored by the Jewish Council for Education & Research that sought to have young Jews encourage their retired grandparents residing in Florida to vote for presidential candidate Barack Obama.

What: Ms. Silverman’s fame didn’t hit home for Dan Sterling, executive producer and head writer on her show, until a visit to Las Vegas with Ms. Silverman when they were mobbed by fans. But, he said, despite now being widely recognized, she continues to be gracious to her fans, a favor they return. While she was picketing during the writers strike, “People driving by would honk and yell, ‘I’m f***ing Matt Damon, too,’” Mr. Sterling said.