Our Picks From Lady Gaga to Ciara, Best and Worst Dressed of the WeekNatalie Portman stuns in Dior, Allison Williams rocks a vibrant jacket, and more of this week's best and worst dressed.The Fashion Beast Team11.01.13 4:20 PM ETNatalie Portman stuns in Dior, Allison Williams rocks a vibrant tangerie jacket, and Ke$ha channels the 70s... in a very bad way. Plus, more of this week's best and worst dressed. Anita Bugge/WireImage via GettyBest Dressed, Vision in White: Natalie PortmanFor the Berlin premiere of Thor on October 27, Natalie Portman looked classic and elegant in a white, strapless silk gown styled with a black silk belt, clutch, and simple diamond earrings. Fernanda Calfat/GettyBest Dressed, Winning the LBD: Diane KrugerDiane Kruger looked fitting at Chanel's Little Black Dress event in Sao Paolo wearing... a LBD by Chanel. The actress wore a strapless dress with embroidered flowers from the brand's Spring 2013 collection and a pair of Stuart Weitzman heels. Astrid Stawiarz/GettyBest Dressed, Pop of Color: Allison WilliamsGirls star Allison Williams sported a clean-cut, all-white ensemble to Marie Claire's Power Women Lunch on October 30. The actress paired her sleeveless top and trousers from Calvin Klein's Spring/Summer 2014 collection with a vibrant orange wool coat. Frederick M. Brown/GettyBest Dressed, Give Me a Smooch: Hailee SteinfeldKisses all around! In typical Hailee Steinfeld fashion, the young Hollywood actress killed the red carpet on October 28 for the premiere of Ender's Game in a one-sleeved white top featuring sequined red lips and simple black trousers and pumps, all by Saint Laurent. Ben Gabbe/GettyBest Dressed, Hints of Floral: Kate BosworthKate Bosworth attends the Big Sur premiere on October 28 in NYC wearing a black floor-length Christopher Kane gown with subtle yet feminine floral appliqués at the neck and waist. Capital Pictures/Sipa USAYou Decide, What's On Her Head?: Lady GagaIs Gaga turning heads in a good or bad way? The singer wore a sleek, high-low black dress coat from Alexander McQueen's Pre-Fall 2013 collection. The knee-high leather boots and large handbag coordinate perfectly -- but is the eye-covering Philip Treacy hat a bit too Halloween for every day? Charles Sykes/APWorst Dressed, Does She Have a Mirror?: Mariah CareySinger Mariah Carey took the stage at BET Networks' Black Girls Rock! on October 26 in an ill-fitting ensemble. The low-cut crop top and hip-hugging skirt showed way too much for comfort. Put it away, Mariah! Splash NewsWorst Dressed, Almost Famous: Ke$haIs Ke$ha trying to convince us she's Penny Lane from Almost Famous? Good try -- but the neon-pink paisley suit, rocket tee, and John Lennon-inspired glasses look like a seventies Halloween costume gone bad. Bob Levey/GettyBest Dressed, Pulling an Angelina: CiaraCiara arrived at The Hotel Derek in Houston, TX on October 28 wearing a cut-out, in too many places, dress. The exposed leg, middriff, and undercleavage -- put some clothes on, girl! TwitterWorst Dressed, Girl Gone Wild: Miley CyrusYes, we know it's Halloween, but Miley Cyrus as rapper Lil Kim just gives us the creeps. The exposed boob, the nipple pasties, the fuschia-overload! Miley looks more like Hannah Montana gone raving.