3. Captain Marvel
When Marvel Comics bumped up long serving hero Carol Danvers from Ms. Marvel to Captain Marvel in 2012 (even though, as her military rank is Major, it's also kind of a demotion), it was clear that they had ambitious future plans for the character. The latest of many Captain Marvels (not to be confused with DC's own Captain Marvel AKA Shazam), Danvers has the powers of superhuman strength, flight and can shoot explosive blasts of energy from her fingers. Like Captain America, she has a military and espionage background so the character could compliment the world of S.H.I.E.L.D. and the Avengers that already exists in the Marvel Cinematic Universe. When it comes to female Marvel heroes who deserve their own solo movie, it's the new Captain Marvel who is at the top of most fans' lists.
How likely is it? As has already come up when talking about Agent Carter, Marvel have their film schedule fairly set in stone for the next couple of years. Their "Phase 2" will involve the various films that lead up to 2015's Avengers: Age of Ultron, while "Phase 3" will then begin with Edgar Wright's movie of Ant Man. There are, however, fairly strong indications from Marvel that a Ms./Captain Marvel movie will be part of their Phase 3. Earlier this year, there were reports that a Carol Danvers feature script had already been completed. Meanwhile, the studio's co-president Louis D'Esposito commented last month that: "There's obviously a drumbeat that is banging louder and louder that we want a female leader superhero" before directly referencing Captain Marvel as a possible future development. For now, it's a case of watch this space, but it seems that Carol Danvers will arrive on the big screen within the next three or four years.
Who should star? Former Battlestar Galactica Starbuck Katee Sackhoff is definitely the internet's favourite choice for the part and has been keen publicly to express her interest in Captain Marvel. Strong, independent, and military trained, Carol Danvers would seem to offer Sackhoff the perfect role to make the transition from supporting actor to lead. Marvel is also reportedly looking at Ruth Wilson (from Luther), Yvonne Strahovski (Chuck and Dexter) and Emily Blunt for the part. Marvel were considering Blunt for the role of Black Widow before it was given to Scarlett Johansson and she has previously expressed an interest in working with them, making her a pretty likely candidate.