Here're the ones i've got so far, if anyone wants to complete the list, please do so:
Heidi Klum in Galliano
Anne Hathaway in Marchesa
Saoirse Ronan Alberta Ferretti
Nancy Walls in Dior
Sarah Larson in Valentino Couture
Kelly Preston in Roberto Cavalli
Amy Adams in Proenza Schouler
Michelle Lee in Marchesa
Jessica Alba in Marchesa
Amy Ryan in Calvin Klein
Laura Linney in Michael Kors
Jennifer Garner in Oscar de la Renta
Helen Mirren in Georges Chakra
Miley Cyrus in Valentino
Kerri Russel in Nina Ricci
Marion Cotilliard in Jean Paul Gaultier Couture
Cameron Diaz in Dior
Rosamund Pike in Roland Mouret
Hilary Swank in Versace
Katherine Heigl in Escada
Cate Blanchett in Dries van Noten?
Rene Zellweger in Elie Saab
Tilda Swinton in ?
Rebecca Miller in Christian Lacroix
Penelope Cruz in modified Chanel Couture
Keisha Whitaker in ?
Anne Marie Duff in ?