Megan Fox solidified her bombshell status with Michael Bay's Transformers franchise, but when the third installment — and one of this Summer's most anticipated blockbusters — opens June 29, Shia LaBeouf will have a new leading lady at his side. The gorgeous Rosie Huntington-Whiteley is stepping in, and taking on her first big-screen role as the beautiful-cum-tough girl lead. We realize, of course, that both women elicit a jaw-dropping reaction when they step on the red carpet, but in honor of Transformers: Dark of the Moon's opening tomorrow, we're asking you to pick a favorite. Will you choose former Victoria's Secret model Rosie's English-rose beauty, or Megan's dark, just-a-little-dangerous sexiness? Click through for 25 of Megan and Rosie's hottest red carpet styles, and decide who takes this style battle.