Best Party Performances

Rihanna

At In Style's Salute to Grammy Fashion, superstar Rihanna helped kick off Grammy weekend with an eight-song set that included hits like "Hate That I Love You," "Pon De Replay," and "Don't Stop the Music." The Caribbean queen wore a black ensemble and accessorized with a sparkling mic and back-up dancers to bring out her inner rockstar. "Put your hands up!" she instructed the crowd before launching into "Shut Up and Drive."

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Alicia and Justin Team Up at Keep a Child Alive's Black Ball

The Keep A Child Alive Black Ball hit a high note when Alica Keys, Justin Timberlake, Adele and Daughtry treated the crowd-which included Queen Latifah and Jessica Alba-to some inspired performances. "To be supported by people you admire is unbelievable," Keys said when asked how it felt to be backed up by her famous friends.

Kanye West Hypes the Brooklyn Ball

In a mash-up of art, fashion and music Takashi Murakami, Louis Vuitton Artistic Director Marc Jacobs and Kanye West combined their influences to stage the ultra-hip Brooklyn Ball at the Brooklyn Museum of Art. West-the self-proclaimed "Louis Vuitton Don"-hit the stage to perform hits like "Gold Digger" and "Stronger."

Mary J Blige at the Cinema Against AIDS Gala in Cannes

At the 13th annual amfAR Cinema Against AIDS gala in Cannes, Mary J. Blige inspired Madonna, Sharon Stone and Natalie Portman with a three-song set that included a cover of U2's classic, "One." "Do you want to be lifted up?" Blige asked the crowd before launching into "Family Affair," which eventually got even Diddy onto his feet.

Miley Cyrus Rocks the 2008 Kids' Choice Awards

Jessica Alba

and Cameron Diaz risked a sliming to attend the annual Kids Choice Awards, where Miley Cyrus joined a lineup that also included fan favorites The Jonas Brothers. In addition to picking up two trophies, Cyrus belted out "G.N.O." (Girls Night Out) for the crowd of screaming tweens.

Jay-Z and DJ AM Bring Music Back to the L.A. Palladium

Hayden Panettiere

, Ellen Pompeo and Jonah Hill were among the crowd who turned up to celebrate the re-opening of L.A.'s legendary Hollywood Palladium. Rap legend Jay-Z marked the occasion by hitting the stage with friend DJ AM-performing for the first time since surviving a plane crash earlier this month-and a twelve-piece band. Panettiere's favorite Jay-Z song? "I got 99 Problems," rapped the actress on the carpet, before heading inside to kick off her heels and dance.

Michael J. Fox Jams at the Night to Remember Benefit

Micheal J. Fox

joined The Who's Roger Daltrey on stage to entertain famous friends like Julianne Moore and Ben Stiller-while raising more the 4 million dollars for The Michael J. Fox Foundation for Parkinson's Research-at the 2008 Night to Remember benefit in New York City.

Justin Timberlake and Beyonce at Fashion Rocks

Dynamic duo Justin Timberlake and Beyonce lit up the stage of Radio City Music Hall when they channeled Marvin Gaye and Tammi Terrell for a performance of "Ain't Nothing Like the Real Thing" at the fifth annual Fashion Rocks concert in New York. The two also kept it down in Motown for earlier solo performances: Justin was as smooth and sexy as always, singing Gaye's "Got to Give It Up," and Beyonce tore down the house belting out "At Last" by Etta James (who was in the audience!) giving the crowd a preview of what's to come when she plays the iconic singer in the upcoming film Cadillac Records.