1. Red Skull
The Red Skull was "killed" when he finally got his hands on the Tesseract (better known to comic book fans as the Cosmic Cube) at the end of Captain America: The First Avenger. However, you never really saw him die. Instead, it appeared as if he may have been transported elsewhere, something which makes a return seem like a definite possibility. Assuming the Red Skull was indeed taken to another realm, there's every chance that, like Captain America, he was frozen in time. A great way of explaining his return could be when all those portals were opened in Thor: The Dark World, or possibly even some sort of development with the Terreract in the upcoming Avengers: Infinity War. The only thing which makes this unlikely as of right now is Hugo Weaving's comments that he doesn't want to reprise the role. It would be a great shame to lose the actor, but it actually wouldn't be in the least big difficult to recast a villain who looks like this. Either way, it's essential that the Red Skull return - his story with Cap feels far from over. Which other MCU characters could return? Share your preferred resurrections down in the comments.