WACKY: Katy Perry made her vote public, performing in a skintight Obama dress at a rally for the President of the United States in Las Vegas.

BEST: Leighton Meester rocked a powerfully patterned Mary Katrantzou cocktail dress with Christian Louboutin heels to her Flaunt magazine bash in Los Angeles.

BEST: Julianne Hough glammed up in Naven for the Samsung Galaxy Note II bash in Beverly Hills, flashing her flat abs in the two-piece look.

BEST: Rachel Bilson added a dash of color to the Los Angeles premiere of Fun Size, wearing a one-shoulder Preen number with grey suede heels.

BEST: Viola Davis donned a monochrome Max Mara gown to the Fashion Group International dinner in New York City, adding a Swarovski clutch and bling.

BEST: Halle Berry looked sizzled hot in Dolce Gabbana at the Los Angeles premiere of Cloud Atlas, adding Sutra earrings and grey Versace heels.

WORST: Talked about a hiked up hemline! Sofia Vergara donned a very short and tight spandex dress to the Domingo Zapata art event in NYC, adding stiletto booties and a red clutch.

WORST: Jennifer Hudson had a little too much going on with her Versace look at the opening of the Italian brand’s New York City store.

WORST: Fashion stylist to the stars Rachel Zoe couldn’t saver herself from a style slip-up at the Los Angeles party for London Showrooms.

BEST: Stacy Keibler hit Rent the Runway’s Our Runway bash, wearing a totally adorable Nanette Lepore eyelet dress with nude sandals.

BEST: Kristen Stewart showed off her luscious legs in a Louis Vuitton romper and Brian Atwood heels at a Tokyo press event to The Twilight Saga: Break Dawn Part 2.

BEST: Penelope Cruz was a golden girl at the London premiere of Skyfall, wearing a sparkling L’Wren Scott gown.

WORST: Brooke Shields couldn’t pull off this lilac and yellow Angel Sanchez look at the Alzheimer’s Association Rita Hayworth gala in New York City.

WACKY: Mena Suvari sported an eccentric ensemble to the Maison Martin Margiela collection for H&M party in New York, which included a nude sleeved top with a bra applique.

BEST: Sexy and single, Katie Holmes hit Narciso Rodriguez’s Kohl’s launch party in New York, wearing a $70 dress from his collection with nude heels and black and gold clutch.

BEST: Renee Zellweger looked gorgeous in grey at the 29th Annual Fashion Group International Night of Stars, wearing an off-the-shoulder Carolina Herrera cocktail dress with Christian Louboutin heels.

BEST: Rosie Huntington-Whiteley showed off her supermodel style in Jason Wu at the Samsung Galaxy Note II launch in Beverly Hills.

WORST: Rita Wilson attempted to wear a sexy Versace dress to the Los Angeles premiere of Cloud Atlas, but the look was a bit too edgy for her.

WORST: Vanessa Hudgens flopped on the fashion front in For Love of Lemons at the New York Television premiere of The Carrie Diaries, pairing the ab-exposing number with black booties.