7. Zatanna - Eva Greene
Zatanna has already appeared on our screens in Smallville so it's not completely unfeasible to demand another appearance. Eva Greene offers the perfect mix of beauty and sex appeal - it helps that she's one hell of an actress too. There were rumours that she would appear as Catwoman in The Dark Knight Rises, but I think Zatanna would be a better fit for her. Her role as Vesper in Casino Royale proves she could nail the mysterious allure of Zatanna perfectly. If there's one area where The Avengers failed, it's its lack of strong female characters. DC boasts a huge gallery of female superheroes and while Zatanna might be difficult to incorporate, her inclusion could be a masterstroke if done right. The Justice League of America movie needs to establish its own distinct universe away from Nolan's (unless those other rumours are to be believed) so embracing characters such as Zatanna would be the perfect way of setting up a more cosmic tone.
Notable Mentions: Mila Kunis, Julia Voth, Ashley Greene