Following an evening of incredible fashion at the Costume Institute Gala at The Metropolitan Museum of Art last night, we've been matching up celebrities in a series of fashionable face-offs.
And no relationship is safe from this competition!
Gossip Girl co-stars Leighton Meester and Blake Lively were pitted against one another earlier in the day... but that's nothing compared to the match-up below!
Sisters Ashley Olsen and Mary-Kate Olsen were spotted on the red carpet, each at her thin, unfashionable best. Compare the siblings below and then vote in our poll:
Who looks better?

























May 5th, 2009 3:22 PM
Mary-Kate Olsen looks great but needs bright colours but i'll give her my vote
I am a great fan offffff herrrrrrrrrr and her sis'
May 8th, 2009 5:09 AM
Mary-Kate looks dishabille
but i think...
they look both great!!