The stars of Gossip Girl pulled out the stops to celebrate their 100th episode at Cipriani Wall Street in New York City Saturday.

"If you go into the wardrobe room you see all these pictures on the wall of everyone when we first started, and I swear some of the kids look like they're 12," Matthew Settle, 42, told Us Weekly. "To see them now, they've all grown into young adults."

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Blake Lively -- who dazzled in a lilac hand-dyed Marchesa dress with fish embroidered detail -- is one of those stars, according to Settle.

"With Blake, it's extraordinary what she does with herself. I don't even think she needs a stylist -- she knows her way around Bergdorfs now."

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The 24-year-old actress (who also wore Versace heels and Lorraine Schwartz earrings) wasn't the only Gossip Girl star who wowed on the red carpet. Leighton Meester -- whose character is planning a royal wedding later this season -- looked ethereal in a Balmain dress and Jimmy Choo shoes.

Meester's 26-year-old costar Michelle Trachtenberg looked equally radiant in a Rebecca Taylor jumpsuit, Erickson Beamon jewelry, Fendi shoes and a Stella McCartney clutch. "I was going for a vintage feel," she told Us. "I did my own makeup!"

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Kelly Rutherford -- who's played Lily van der Woodsen for five seasons -- also turned heads in a Peter Som dress. The 43-year-old actress accessorized her look with Van Cleef & Arpels jewelry and Christian Louboutin heels.

Tell Us: Who was the best-dressed star at Saturday's Gossip Girl party?

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