A huge number of superheroes have now been adapted onto the big screen. Everyone from Superman to Ghost Rider, Spawn to Storm, Spider-Man to Supergirl, The Mask to Wolverine and Hellboy to Black Widow have had live action interpretations depicted in big-budget Hollywood blockbuster movies.
In many of those cases, the adaptations have been roaring successes and, in other cases, they've flopped terribly. However, the one thing that pretty much every movie version of any given superhero has in common is that several actors were initially in line to play the part in question - and some of those actors came remarkably close to doing so instead of the actors who ultimately went on to portray them.
Every single one of our favourite movie superheroes could have turned out very differently, had any of the other actors who had been considered to play them ended up donning the capes, spandex and armour that comes with fighting evil in comic book movies and this article is going to take a look at just some of the stars who could have taken on some of those roles. On that note, here are ten superheroes who were very nearly played by completely different actors...
10 Superman (Nicolas Cage)
To date, the likes of Christopher Reeve, Brandon Routh and Henry Cavill have all played Superman on the big screen, but there was a time when Nicolas Cage was actually officially announced to play the Kryptonian hero and was even filmed wearing the outfit he would have donned for the role - footage of which has recently come to light on the internet.
The film - which was going to be called Superman Lives - was never actually made, but it would have been produced at some point in the 1990s, with Tim Burton directing and Jon Peters producing, and would have seen the Man of Steel facing off against a trio of his classic villains in Lex Luthor, Brainiac and Doomsday.
Selected other actors who could have played Superman: Burt Reynolds, Paul Walker, Ashton Kutcher, Josh Hartnett, Matt Bromer.
9 Iron Man (Tom Cruise)
Robert Downey, Jr. has made the character of Tony Stark AKA Iron Man his own since his first appearance in the Marvel Cinematic Universe franchise back in 2008. He has since gone on to appear in three Iron Man solo movies, two Avengers movies and in the final scene of the Incredible Hulk movie. But the character could have been played by Tom Cruise.
Cruise was in line to play Stark, but his diva behaviour ultimately prevented that from happening. He wanted his face to be visible at all times - which would have meant a total redesign of the classic Iron Man armour and, as a result, he was taken out of contention.
Selected other actors who could have played Iron Man: Sam Rockwell, Clive Owen, Hugh Jackman, Nicolas Cage, Timothy Olyphant.
8 Hulk (Steve Buscemi)
Bruce Banner AKA the Hulk has now been played in live action movies by Eric Bana (in Ang Lee's standalone Hulk movie from 2003), Edward Norton (in the Marvel Cinematic Universe's The Incredible Hulk in 2008) and Mark Ruffalo (in the Marvel Cinematic Universe in the Avengers movies, since Norton's departure). He could, however, have been portrayed by a very different actor.
Reservoir Dogs and Con Air star Steve Buscemi - who is actually much closer to looking like comic book Bruce Banner than any of the aforementioned actors - tested for the role in Ang Lee's movie and was very close to landing it.
Selected other actors who could have played Hulk: Joaquin Phoenix, Jeff Goldblum, Tom Cruise, Johnny Depp, David Duchovny.
7 Black Widow (Emily Blunt)
The very beautiful Scarlett Johansson has nailed the role of Natasha Romanoff AKA Black Widow since her first appearance as the character in 2010's Iron Man - going on to portray the former assassin in two Avengers movies and Captain America: The Winter Soldier - but she wasn't actually Marvel Studios' first choice to play the part.
The Devil Wears Prada star Emily Blunt was actually offered the role outright and only missed out due to a scheduling conflict - she had commitments on Gulliver's Travels to fulfil. It's fairly obvious which actress got the better deal in hindsight.
Selected other actors who could have played Black Widow: Jessica Biel, Gemma Arterton, Natalie Portman, Jessica Alba, Angelina Jolie.
6 Captain America (John Krasinski)
Chris Evans took on his second major role in a Marvel comic book movie in 2011 when he starred as Captain America in Captain America: The First Avenger, having already portrayed the Human Torch in two Fantastic Four movies a few years earlier. He has since portrayed the character in two Avengers movies and Captain America: The Winter Soldier and has done a great job.
A very different actor could have donned the famous red, white and blue, however - The Office star John Krasinski. The funny man tested for the role and was strongly considered for it but, ultimately, Marvel Studios opted for Evans - and that's probably for the best.
Selected other actors who could have played Captain America: Alexander Skarsgard, Channing Tatum, Ryan Phillippe, Will Smith, Sebastian Stan.
5 Green Lantern (Jack Black)
2011's Green Lantern was so terrible that it was almost comedic in some people's eyes - but the fact is that wasn't the intention and Ryan Reynolds was cast with a serious franchise in mind. A modest box office profit didn't make up for the fact that the movie was awful, but it could have been a whole lot worse.
There was actually an idea to cast Jack Black in an actual comedy adaptation of the Green Lantern concept. He would have played Kyle Rayner, as opposed to Reynolds' Hal Jordan (although some sources suggest he'd have played an original character called Jed), and it would undoubtedly have been even worse than the version that was actually produced.
Selected other actors who could have played Green Lantern: Bradley Cooper, Jared Leto, Sam Worthington, Chris Pine, Justin Timberlake.
4 Batman (Bill Murray)
Batman has famously been played by a number of actors in big-budget Hollywood productions. Michael Keaton, Val Kilmer, George Clooney and Christian Bale have all portrayed the Dark Knight already and Ben Affleck is due to take on the role in 2016's Batman v Superman: Dawn of Justice and beyond that.
However, Peter Venkman himself - Bill Murray - could have portrayed the Gotham hero in the 1989 movie, up to the point when Warner Brothers decided to avoid the idea of a camp offering in the style of the Adam West television show. As brilliant an actor as Murray is, him playing Batman just wouldn't have worked.
Selected other actors who could have played Batman: Clint Eastwood, Mel Gibson, David Boreanaz, Ray Liotta, Charlie Sheen.
3 Spider-Man (Edward Furlong)
Spider-Man is arguably Marvel's most popular character and, to date, he has had two different solo franchises. Tobey Maguire played the Webbed Wonder in three films between 2002 and 2007 and, more recently, Andrew Garfield did so in 2012 and 2014's Amazing Spider-Man movies. Tom Holland will take on the role now that the character has been drafted into the Marvel Cinematic Universe.
A far more unlikely candidate - especially given his status these days - to take on the role back in the 1990s was Edward Furlong. The then-young actor who had portrayed John Connor in Terminator 2: Judgement Day would have portrayed the hero had James Cameron's Spider-Man movie been made. The movie would also have included the likes of Lance Henriksen as Norman Osborn and R. Lee Ermey as J. Jonah Jameson.
Selected other actors who could have played Spider-Man: Tom Cruise, Leonardo DiCaprio, Jake Gyllenhaal, James Franco, Chandler Riggs.
2 Star-Lord (Glenn Howerton)
Star-Lord was one of the surprise success stories in movies in 2014 - as was Guardians of the Galaxy in general - and that was all thanks to Chris Pratt. The Parks and Recreation actor shed some excess weight, piled on the muscle and delivered a charming and hilarious performance as the hero/outlaw otherwise known as Peter Quill. While he was the first choice for the role, he wasn't the only man in for it.
Glenn Howerton came very close to landing the part after impressing in his audition. Sadly for the star of It's Always Sunny in Philadelphia, Chris Pratt had already auditioned and wowed James Gunn et al. Had that audition not already happened, there's every chance that Howerton would have been cast on the spot.
Selected other actors who could have played Star-Lord: Eddie Redmayne, Joseph Gordon Levitt, Aaron Paul, John Krasinski, Lee Pace.
1 Wolverine (Bob Hoskins)
6' 2" handsome Australian actor Hugh Jackman has made Wolverine one of the most iconic comic book movie heroes since he was cast as the character from relative obscurity back in the year 2000. He has since reprised the role six times, including a cameo in X-Men: First Class.
It might come as something of a surprise, then, to find out that the late, great (and 5' 5") Bob Hoskins was considered for the role back in the 1980s. As a matter of fact, Hoskins was far closer in appearance to the comic book version of Wolverine - short, stocky and gruff - so it shouldn't really be that shocking that he was considered. His Wolverine would have been very different to Jackman's, however.
Selected other actors who could have played Wolverine: Dougray Scott, Edward Norton, Russell Crowe, Thomas Jane, Glenn Danzig (who isn't even actually an actor at all!).