6. Ms. Marvel
Marvel ComicsMs. Marvel has long been touted as being introduced in to the Marvel Cinematic Universe and her arrival is surely imminent. She could be the super-powered female hero that the franchise is crying out for and could quite easily become the face of the whole project. She could even be introduced in Avengers: Age of Ultron - though this hasn't been confirmed yet, meaning the part would only be a small one (perhaps during or after the credits) if she did end up appearing, but she'd certainly be a great addition to the Avengers roster for future movies. As an air force officer in the comic books, Carol Danvers was exposed to an explosion involving alien technology. Consequently, she was imbued with an array of superpowers including super strength, flight, energy projection and absorption and enhanced agility and stamina. She would, therefore be a very big gun on the scale of Thor and an attractive and relatively well-known actress playing her could easily make her the Marvel Cinematic Universe's star attraction.