Collar up or down? Back in October, Rachel Weisz attended The Brothers Bloom premiere in London in Roland Mouret's black and cream assymetrical dress with black pumps, a sleek updo and the flowing collar up. This past weekend, Jessica Alba wore the same dress to the Vanity Fair Oscar party with a gold clutch, black peep toes and the cream collar off her shoulder.

This time, MTV reality stars past and future go toe to toe. At the celebration of the 2009 'What is Sexy?' List in New York this month, Adrienne Bailon wore this black one shouldered BCBG dress with black patent leather pumps and loose waves. While performing on Dancing With the Stars in September, Jessica Simpson wore the same dress with gold hoops and studded sandals.