6. Maria Hill/Agent 13
Maria Hill made her debut in the comics as Nick Furys replacement while he was MIA (again). I wont spoil Agent 13 for the uninitiated as she will appear in the upcoming Captain America sequel soon enough. Suffice to say that they are both agents of SHIELD, and represent strong female central characters that are still sadly too few in film. Its time women as the mind and muscle in espionage films were considered a given. Nick Fury is very much in charge in the MCU, putting Hills character is in a subordinate role unlike her take charge Comic book counterpart. Still, SHIELD is a massive multinational organization; there is plenty of room for her to give orders to one of the best field agents ever. The trick here is coming up with a problem that at once is worthy of a world full of super beings, but within the wheel house of highly trained, yet not super agents. Enter the Enclave, a group of super scientists that want to rule the world...with science (The Enclave is famous for creating Adam Warlock, which might be the reason he doesnt seem to be in the Guardians of the Galaxy film, which makes me really angry). A mission goes badly and the evidence points to Maria Hill as a traitor. Agent 13 goes after her, after a game of cat and mouse Hill convinces 13 that shes innocent. In the quest to clear her name a final showdown with the Enclave reveals that they are actually the minions of The High Evolutionary! (This would be a second nod to Adam Warlock and an apology for hosing the fans, and also provide a complex villain for future Avengers films).