The G.G. star keeps it casual in textured shorts, a tee and blazer at Janie Bryant's book launch bash in New York City.
Part court jester, part Frederick's of Hollywood eveningwear, Leighton wears the world's most bizarre black lace jumpsuit courtesy of Marchesa for a Harry Winston jewelry party.
Blake blends with the bejeweled background in this dazzling bolero with gray mini and burgundy tights as she unveils the Swarovski star to crown the 2010 Rockefeller Center Christmas tree.
Blair's alter ego tones down the outrageousness for the CMA Awards in this pretty Emilio Pucci print dress but doesn't lose her edge thanks to a killer pair of Jimmy Choo heels.
What else would you wear to a Tokidoki sneaker launch but black lace and boots that look like they could kill, of course.
Bonus points for the black lace Chanel dress at the CFDA Awards but the flesh-colored bra (which shows up under the photographers' lights) was a bad call.
A floral crochet Marc Jacobs dress is the Gossip girl's pick for the Country Strong premiere in Nashville. Interesting.
Fresh from Vivienne Westwood's Fall 2010 runway, Blake tries to recapture the mismatched magic at the Realm Boutique opening in NYC.
Whoa. Meester suffers an '90s moment with this cropped top and mini at the Proenza Schouler show in NYC.
Momsen sticks to her traditional style—mini, thigh-high boots and black eyes—for the launch of Madonna's Material Girl Collection.
At least Blake gets points for originality for this Lanvin halter dress with giant bee broach at the Scream Awards.
Blake graces a Tiffany & Co. event in a black lace and burgundy tulle dress by Elie Saab paired with Louboutin heels that are almost a perfect match.
The blonde beauty flaunts her gorge gams in an Elie Saab mini while visiting The Late Show with David Letterman.
Leighton goes much cuter than Blair would ever allow in this floral Marc Jacobs dress at V magazine's New York issue party.
At the Boston premiere of The Town, Blake models a more grown-up look. But the peek of lace adds a splash of sexy, making this Antonio Berardi dress a good mix of class and sass.
Garters, black leather and stripper heels...exactly what you'd expect to see on David Letterman's show. Not.
A vibrant Blake visits Live with Regis & Kelly in New York wearing a heavily embellished Matthew Williamson jacket with a blue leather pencil skirt.
Serena van der Woodsen's alterego hits the Toronto Film Festival to promote The Town—she'd be hard to miss in this red hot Chanel Couture dress embellished with roses around the hips.
Miss Upper East Side hits Soho for the reopening of the Chanel boutique, paying homage to the design house in a striped and sequined Couture dress.
Versus bustier dress. Good for Fashion's Night Out. Or a dominatrix dungeon. Whatever.
The Gossip star attends Fashion's Night Out in a bright and busy frock from Marchesa.
Leighton gets into the beachy vibe at the 2010 Teen Choice Awards in an Emilio Pucci tunic and pom-pom Louboutin heels.
At Madonna's line launch in NYC, Tay ditches the no pants trend but still manages to bare some skin, natch.
At the Twelve premiere, Blake supports her fellow G. Girl star (Chace Crawford), but doesn't do right by her fashion in this polka-dot-daisy sheer-panel Chanel mini.