Superhero movies are big bucks at the box office and have made monster stars of all of the actors who have taken on these heroic roles.
Sometimes it is hard to believe that any other actor could have been or was considered for certain roles.
Take a look at some of actors that also took on some of the biggest film roles of recent years: pretty glad that most of these did not work out.
- Tom Cruise as Iron Man
When it comes to Iron Man, you cannot see anyone other than Robert Downey Jr playing the flamboyant billionaire playboy.
Tom Cruise was the actor who was expected to take on the role of Tony Stark, having been linked to the project for many years. He was also set to co-produce the film.
However, Cruise left the movie due because he was unhappy with the script. Cruise perhaps would not have got the cheek and charm of Stark that makes him such a fantastically likeable character.
Clive Owen was another actor who was overlooked as Jon Favreau took a punt on Robert Downey Jr.
Iron Man was the movie and the role that revitalised Downey Jr's career. This role fit him like a glove, and he has re-established himself as one of Hollywood's biggest stars. Iron Man is now a billion dollar franchise.
- Dougray Scott as Wolverine
Wolverine is the role that made Hugh Jackman a star, and he has gone on to appear in all of the X-Men movies since he debuted in X-Men.
It is hard to believe that Jackman was not the first actor cast in this role. Dougray Scott was brought on board the film in 1999.
However, it wasn't to be for Scott, as he had to pull out of the project due to a scheduling conflict with Mission: Impossible II.
The likes of Russell Crowe, Gary Sinise, and Viggo Mortensen were also considered for the role.
It was Jackman who landed the part, and he has not looked back as he has enjoyed success with the X-Men franchise and stand-alone Wolverine films.
- John Krasinski as Captain America
Captain America will be returning to the big screen later this year to do battle with the Winter Soldier: his second stand-alone film for this character.
Chris Evans is back as Steve Rodgers, but the role almost went to funnyman John Krasinski.
Kraskinski had read for the part and screen tested on several occasions, and looked odds on favourite to scoop this huge part.
He had seen off the challenge from the likes of Channing Tatum, Ryan Phillippe, Mike Vogel, and Garrett Hedlund.
Krasinski is best known for his comedy work, so if he would have worked as Steve Rodgers will never be known.
The role was snatched away from him by Chris Evans - apparently, Evans never even tested for it. Since then, he has become a huge part of the Marvel family, and spars well with Robert Downey Jr in Avengers Assemble.
- Nicolas Cage as Superman
Nicolas Cage is no stranger to comic book movie having starred in Ghost Rider. However, the Oscar winner was under consideration for the role of Superman.
The movie was set to be brought to the big screen by Warner Bros, and Tim Burton was on board to produce. The script was originally penned by Kevin Smith.
This project never went ahead.
Other director's tried to bring Superman to the big screen over the years, and the likes of Will Smith and Josh Harnett were considered for the role of Superman.
Superman eventually returned to the big screen in 2006 with Superman Returns. Bryan Singer was in the director's chair, while unknown Brandon Routh took on the title role.
- Emily Blunt as Black Widow
We were introduced to the character of Black Widow for the first time in Iron Man 2 back in 2010.
Emily Blunt had landed the role of Natasha Romanoff alongside Robert Downey Jr - Jon Favreau was set to return to the director's chair.
Sadly, Blunt had to pull out of the film as she had filming commitments to Gulliver's World. I am not sure that she would have been the right fit for this film.
Despite missing out, she had gone on to work on some exciting projects including Looper and The Adjustment Bureau.
Marvel may have missed out on Blunt, but they managed to land an actress just as exciting, as Scarlett Johansson brought Black Widow to life.
She made her debut in Iron Man 2 and returned in Avengers Assemble. We are going to be seeing her in Captain America: The Winter Solider and Avengers: Age of Ultron. Could a solo film be just around the corner?
- Jim Caviezel as Cyclops
Jim Caviezel is not the type of actor that you would associate with the superhero big budget blockbuster, but he landed the role of Scott Summer in X-Men.
It was a tight race for the role of Cyclops, as Caviezel saw off the challenge from Edward Norton, Jude Law and Owen Wilson.
However, it was not to be for the Passion of the Christ actor as he was forced to drop out of the project due to a scheduling conflict with Frequency.
The role of Cyclops eventually went to James Marsden, who went to star in X-Men, X2 and X-Men: The Last Stand.
Other actors that were considered for superhero roles include Leonardo DiCaprio as Spider Man and Bill Murray as Batman.