7) Secret Invasion
One of Marvel’s biggest successes so far is Captain America: The Winter Soldier. Many elements made the film a success, and one of them was the conspiracy thriller aspect – with HYDRA controlling S.H.I.E.L.D., Cap and his loyal band had no idea who they could trust.
If Marvel wanted to do a similar movie but on a bigger scale in the future, they should really tackle Secret Invasion. This crossover storyline from 2008/2009 revealed that shapeshifting aliens the Skrulls had been replacing Earth’s Mightiest Heroes with imposters for years. Naturally, the event saw the Avengers struggle to trust each other, as they sought to find out who was who.
The only issue with adapting this event is that the rights to the Skrulls rest with 20th Century Fox. However, though it would be a shame if a movie version didn’t feature them, they really aren’t the be-all-and-end-all of the story and their place could easily be filled with any alien race.