1. Heath Ledger (The Dark Knight)
Heath Ledger’s remarkable portrayal of the Joker in The Dark Knight is one that will never be forgotten. The actor posthumously won the Academy Award for Best Supporting Actor, the first time a comic-book movie received an Oscar for achievement in acting. Nolan initially approached Ledger to discuss playing the role of Batman in Batman Begins.
Ledger told Nolan that he was not interested in taking part in a superhero film. Nolan explained in a Q&A for the Film Society of Lincoln Center,
“He was quite gracious about it, but he said, 'I would never take a part in a superhero film.' "
2. Tom Hiddleston (Thor)
Tom Hiddleston's portrayal of Loki was incredible, the role fitted him perfectly but he originally auditioned to play the role of Thor. Chris Hemsworth landed the coveted role of Thor beating his brother Liam Hemsworth to it as well.
3. Sam Rockwell (Iron Man 2)
Sam Rockwell portrayed one of the two villains in Iron Man 2, Justin Hammer, a billionaire weapons dealer. In saying this Rockwell originally auditioned to play the role of Tony Stark/ Iron Man. Director, Jon Favreau told the LA Times,
"He was one of the actors I was looking at for Tony Stark. There was some things he would bring to the role that would have been great. Sam is very charismatic and when I was looking at the character there was a list and he had a spot on it, which might have surprised some people. Robert surprised some people, too, though, and now he is Tony Stark, he owns that role. Sam would have come up with interesting and different things."
4. Cillian Murphy (Dark Knight Trilogy)
The Scarecrow/ Jonathan Crane is the only villain to appear in every installment of Christopher Nolan’s Dark Knight Trilogy.
Prior to Cillian Murphy's casting as Crane, he screen tested to play Batman/ Bruce Wayne. The role eventually went to Christian Bale.
5. James Franco (Spider-Man)
Harry Osborn is the role played by James Franco in Sam Raimi’s Spider-Man trilogy. Unknown to most the actor also screen tested for the role of Spider-Man/ Peter Parker.