"I go through stages. Randomly, I'll be attracted to a crazy rocker with tattoos. And I find that I'm extremely attracted to ambition and wit. If it was appropriate to date (co-star) Michael Sheen, I would, but he and his girlfriend (Rachel MCAdams) are so cute. And maybe this is 'You want what you can't have' - Neil Patrick Harris. And, oh, (newsman) Anderson Cooper. I'd be all over that." Twilight star Ashley Greene on her celebrity crushes.