Fashion Faceoff

Sometimes, stylish star minds think alike. You decide: Who wears it better? Vote on Hayden vs. Sienna and more. By Melissa Liebling-Goldberg

LILY VS. CAMERON

The British singer hit the V-Festival in her McQ-Alexander McQueen dress over jeans only a few days before the actress rehearsed in Manhattan for her new film What Happens in Vegas ... in her billowing gray dress.