2. Rooney Mara
While Rooney Mara came to audiences' attentions playing average, girl next door types in the remake of Nightmare on Elm Street and David Fincher's The Social Network, she received the most acclaim when she starred as Lisbeth Salander, the anti-social but brilliant computer hacker in Fincher's version of The Girl With The Dragon Tattoo. Her performance received her an Academy Award nomination for Best Actress and revealed her dramatic depths as an actress. She also gave an intriguingly layered performance earlier this year in Steven Soderbergh's supposed swansong, Side Effects, as a woman who goes on anti-depressant medication that leads to some unexpected, you guessed it, side effects. With these roles, Mara shows that she's not your typical girl next door, romantic comedy actress but an actress who's apt at playing socially maladjusted characters with cold exteriors but vulnerable interiors. I think Mara would make a great Harley Quinn due to her already playing female characters with dark and complex psychologies. I could easily see her starting out as the straight-laced doctor whose mind becomes warped by her sessions with the Joker. The role of Harley will also require the actress to be darkly funny. While Mara, to my knowledge, hasn't had any comedic roles, I think she's strong enough an actress to pull off the twisted sense of humour that Harley shares with the Joker.