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Keira Knightley in Atonement (2007)
Maybe it was the brilliant color, or the beautiful draping, or its role in the steamiest library scene ever committed to film, but even before the movie made its debut, Knightley's emerald gown achieved icon status.
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Serena in Gossip Girl pilot (2007)
When Serena van der Woodsen, played by Blake Lively, shimmied onto the screen in the show's first episode, her sequined Tory Burch would be the first in a long line of covet-worthy looks.
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Michelle Obama at the final night of the Democratic National Convention (2008)
The future First Lady was already making fashion waves with her liberal use of J.Crew, but it was when she picked a floral number from up and coming designer Thakoon for the pivotal final night of the convention that the fashion world knew a new tastemaker was on the scene.
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Michelle Williams at the Oscars (2006)
She may not have taken home the Oscar, but one-half of everybody's favorite hipster couple certainly won over the fashion world in a delicately pleated, daringly mustard-hued Vera Wang.
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Anne Hathaway at the Venice Film Fest (2008)
Taking to Venice's red carpet in this dreamy Atelier Versace gown, Hathaway proved she was true silver-screen material.
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Cate Blanchett at the Oscars (2005)
She's had many, many red carpet triumphs, but the surprising combination of pale yellow and burgundy accents makes this regal Valentino rise above.
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Kate Hudson in How To Lose a Guy in 10 Days (2003)
The star didn't need an ounce of ''frosting'' when she descended the stairs in this slinky canary yellow gown.
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Lady Gaga on her Fame Ball tour (2009)
There would be far more outrageous costumes to come, but the envelope-pushing diva announced her arrival on the scene in a dress made of bubbles.
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Carrie Bradshaw in Sex and the City (2004)
For her final outing on the small screen, our favorite fashion icon wore a swoony Versace gown, which was also the perfect wink to the tutu that started it all.
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Halle Berry at the Oscars (2002)
Berry's tearful acceptance speech would become an Oscar classic — as would her strategically appliquéd gown by the previously little-known designer Elie Saab.
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Jennifer Lopez at the Grammys (2000)
Gowns come prettier, classier, and even skimpier. But J.Lo's down-to-there Versace earned its place in fashion history thanks to an inimitable alchemy of style and star. And double-stick tape.
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Julia Roberts at the Oscars (2001)
Vintage wasn't always in on the red carpet — that is, until Miss Julia wore a show-stopping number from Valentino's 1982 collection to scoop up her Oscar for Erin Brockovich.
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Sienna Miller at Factory Girl premiere (2007)
The star responsible for the renaissance of swingy shifts and contrasting tights gave her best boho look in a Balenciaga babydoll.
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Julia Louis-Dreyfus at the Emmys (2006)
Narciso Rodriguez' figure-hugging gowns would become a staple on the red carpet, but first there was this: the smart white gown with black beaded harness that the Seinfeld alum wore to cart home her New Adventures of Old Christine Emmy.
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Emma Watson at the Harry Potter and the Half-Blood Prince premiere (2009)
For her sixth Harry Potter movie, Hermione came into her fashion own — most memorably in this vintage Ossie Clark number.
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Angelina Jolie at the Mr. and Mrs. Smith premiere (2005)
Who else could pull off a floor-length halter gown made of leather? Only Angie, that's who.
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Renée Zellweger at the Oscars (2001)
The actress had us at the first sight of this sunny Lily et Cie gown.
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Penelope Cruz at the Oscars (2007)
In this sweeping Atelier Versace gown, Cruz defined red-carpet glamour for the 2000s.
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Kate Winslet at the Oscars (2002)
Proving the power of red, Winslet wowed in a simply elegant Ben de Lisi gown.
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Reese Witherspoon at the Golden Globes (2007)
She may have been newly single, but when Reese stepped into the Golden Globes in a short canary yellow Nina Ricci — paired with unexpectedly perfect red kicks — all we were talking about was her razor-sharp sense of style.