For every superhero movie that successfully makes it way to the big screen, there are countless others that get a certain distance into production before falling apart at the seams. And, for every movie that gets made, there are countless other permutations of that film that must exist in parallel universes somewhere; versions in which the script diverges in key ways, or the characters chosen for the film are altered, or the actors chosen to play these heroes and villains are very different. This article will focus on these parallel films in which iconic roles were almost played by wildly different actors and actresses.

Superman has appeared on the big screen eight times, from 1978's genre defining Superman: The Movie to Superman IV: The Quest For Peace; from Bryan Singer's misjudged Superman Returns to Henry Cavill's recent DCEU incarnation. However, there have also been a number of huge Superman projects that have fallen through the cracks over the year:  from Superman Reborn and Superman Lives in the '90s, to Superman: Flyby and Wolfgang Petersen's Batman V Superman in the early '00s. Nicolas Cage was famously signed on for Superman Lives and even did costume tests before the project was shut down, but there were also a huge number of other actors that very nearly wound up playing famous Superman characters over the years. Some of these actors might arguably have been better than what we eventually got and some of them might've been so much worse (and there's also a fair amount that later went on to play other genuinely iconic superhero rules for both Marvel and DC). Read on!

20 BETTER: MATT BOMER AS CLARK KENT/SUPERMAN

Matt Bomer has something of a tortured history with Superman. He voiced the Man of Steel in the 2013 animated movie Superman: Unbound, which made most of his fans happy, but some saw it as scant reward when he had previously been linked with playing Superman in a live-action movie on several occasions. The Magic Mike star was actually cast in Brett Ratner's 2002 project Superman: Flyby, which unfortunately fell apart when Ratner left the production.

Bomer then lost out to Brandon Routh when Bryan Singer finally made Superman Returns in 2006 and his name was again bandied about before Henry Cavill was cast in Man Of Steel. With the requisite good looks and charm, it's not hard to see how Bomer could've made an excellent screen Superman.

19 WORSE: ZACHARY LEVI AS CLARK KENT/SUPERMAN

Zachary Levi is no stranger to superhero movie roles. He is playing the adult superheroic version of Billy Batson in the upcoming DCEU film Shazam! and he also played Fandral, one of the Warriors Three, in blink-and-you'll-miss-it extended cameos in the Thor sequels The Dark World and Ragnarok. Prior to playing these roles, though, Levi had been rumored to have auditioned for the role of Superman in 2010 and was also linked to playing The Flash and Green Lantern.

At the time, he said that the rumors were complete fiction but clarified that he did indeed want to play a superhero, so it's nice that he got there in the end with Fandral and Shazam. Those parts suit him -- we can't help thinking he wouldn't have been quite right for the Last Son of Krypton.

18 BETTER: BRYAN CRANSTON AS LEX LUTHOR

Jesse Eisenberg's portrayal of a younger, twitchier, long-haired Lex Luthor in Batman V Superman: Dawn Of Justice was widely derided by fans and critics alike. It's easy to see director Zack Snyder's thinking in casting against type; Eisenberg's vaguely sinister turn as a young Mark Zuckerberg in The Social Network hinted at a Lex unlike anything we'd seen before.

Sadly, it meant fans didn't get to see Bryan Cranston's version of Lex, which had been heavily rumored for a very long time when the film was coming together. It turned out that Cranston never once spoke to the studio about the role and that his name being linked was just fan-driven hype, which sucks, because Cranston (Breaking Bad) can bring bald-headed menace like no one else!

17 WORSE: ASHTON KUTCHER AS CLARK KENT/SUPERMAN

During a press junket for 2010 action romcom Killers, Ashton Kutcher (That 70's Show) revealed that he auditioned for the role of Clark Kent/Superman at some point in the early 2000s! He said he couldn't remember which director he auditioned for, but reasoned it might have been Brett Ratner, which by our calculations means he was auditioning for Superman: Flyby (which never got made).

He said he was stick thin at the time, looked silly in the costume and added that the whole audition just didn't feel right. He also added that his audition was opposite Keri Russell (The Americans) as Lois Lane, which is interesting. We definitely agree with Kutcher that the idea of him playing Superman just doesn't feel right, but maybe that's doing him a disservice. Maybe.

16 BETTER: RACHEL MCADAMS AS LOIS LANE

Before Rachel McAdams played Dr Christine Palmer in 2016's Doctor Strange, she was rumored to be one of the frontrunners to play Lois Lane in Man Of Steel. The role went to Amy Adams in the end, but sometimes we wish McAdams had bagged it instead. Her performances as Irene Adler in the two Guy Ritchie-directed Sherlock Holmes movies showed an actress capable of showcasing her charm and charisma, while also having an undercurrent of deviousness at all times.

She also starred as a crusading reporter in 2015's Spotlight, which she picked up a Best Supporting Actress Academy Award nomination for. Put those two performances together and you've got a Lois Lane who would be compelling to watch.

15 WORSE: MATTHEW GOODE AS CLARK KENT/SUPERMAN

English actor Matthew Goode worked with director Zack Snyder on 2009's Watchmen adaptation. Goode's name was then thrown around during the casting process for Man Of Steel and at one point there was a rumor that Snyder was going to rely heavily on CGI for scenes of Superman in costume, eliminating the need for the chosen actor to buff up for the role.

In the end, certain reports said it came down to Goode and Henry Cavill, with the Immortals star getting the nod. We think the right choice was made in this instance, as even though Goode is a tremendous actor, he doesn't scream 'Last Son of Krypton' to us.

14 BETTER: VIGGO MORTENSEN AS GENERAL ZOD

Michael Shannon played General Zod in Man Of Steel and wound up being one of the best things about the film, which overall received a decidedly mixed response from fans and critics. Most people agreed Shannon brought the right amount of menace and misguided nobility to the role. But, we wonder how different things would have been if Viggo Mortensen, who was initially rumored to be up for the role, had played the rogue Kryptonian military general?

Mortensen is beloved by geeks for playing Aragorn in The Lord Of The Rings trilogy and is an actor capable of going to extremely dark places for a role. He might have been even better than Shannon.

13 WORSE: JOSH HARTNETT AS CLARK KENT/SUPERMAN

Josh Hartnett was a very big deal in Hollywood in the early 2000s. He had been pegged as the 'next big thing' and was a bankable leading man after roles in Black Hawk Down and Pearl Harbor. During this period he was reportedly offered the chance (and a hell of a lot of money) to play several superheroes, all of which he turned down out of fear of being typecast at a young age.

He turned down Spider-Man, Batman and Superman (when director Bryan Singer spoke to him about Superman Returns). Hartnett likely wasn't right for these parts, but he did later admit that saying no to such huge roles was detrimental to his career. He also expressed regret at one 'no' in particular: turning Christopher Nolan down when Batman Begins was being developed.

12 BETTER: ROBERT DOWNEY JR. AS LEX LUTHOR

Robert Downey Jr. is one of the highest paid actors in Hollywood and a genuine worldwide icon, all thanks to his role as Tony Stark/Iron Man in the Marvel Cinematic Universe. But, how differently could things have worked out if he had played Lex Luthor in 2002's Superman: Flyby?

In a 2012 interview, director McG revealed that he had Downey Jr locked down to play Luthor in his version of the film, which wound up being scrapped before Bryan Singer successfully brought Luthor back to the screen in the shape of Kevin Spacey in 2006's Superman Returns. At the time, Downey Jr was making a comeback with his role in TV's Ally McBeal and we'd imagine he would've brought something special to the role of Superman's arch-nemesis.

11 WORSE: DUSTIN HOFFMAN AS SUPERMAN AND/OR LEX LUTHOR

Superman: The Movie is ground zero for superhero movies. The first big-budget comic book film that was taken seriously by the public, everything that has happened in the subsequent decades can ultimately be traced back to its influence. Christopher Reeve was an unknown when he was hired to play Clark Kent/Superman and he is still many people's ideal image of the Man of Steel.

He certainly looked the part more than another shortlisted actor: Dustin Hoffman, who was riding high at the time thanks to Marathon Man and All The President's Men. Producer Ilya Salkind revealed on a recent commentary track that Hoffman was even sought to play Lex Luthor as well -- producers had dinner with him at Cannes to discuss the part but nothing came of it.

10 BETTER: SANDRA BULLOCK AS LOIS LANE

When Superman Lives was in pre-production in the mid-'90s, with a script by geek icon Kevin Smith, Tim Burton in the director's chair and Nicolas Cage attached to star as Clark Kent/Superman, Sandra Bullock was reportedly Warner Brothers' number one choice to play Lois Lane. To be honest, we struggle to think of anyone at that time who would've been more perfect than Bullock.

She was one of the biggest female stars in the business, with a string of recent hits including Speed, While You Were Sleeping and The Net, and she would've brought a steely determination and undeniable charisma to the role. Sadly, the movie fell apart and Superman didn't make it back to the big screen until 2006.

9 WORSE: JAMES CAAN AS CLARK KENT/SUPERMAN

Legendary character actor James Caan was another actor on the shortlist to play Superman in the 1978 movie. He had become a big name in the '70s thanks to performances in The Godfather and Rollerball but turned down the chance to play the Man of Steel. Before Richard Donner came on-board as director, the script had a lighter tone, which Donner altered before filming began, but Caan balked at the tongue-in-cheek nature of the original script.

In the end it might've been for the best, as Caan is an actor more known for simmering intensity than all-American values and morally upright heroism. Incidentally, Caan also reportedly turned down the chance to play Han Solo in George Lucas' Star Wars!

8 BETTER: ROBERT REDFORD AS CLARK KENT/SUPERMAN

Of all the known actors who were on the shortlist for Superman: The Movie, Robert Redford makes the most sense to us as Clark Kent/Superman. For one thing, he had the kind of all-American square-jawed good looks for it. He was also one of the most bankable leading men in Hollywood at the time thanks to movies like The Great Gatsby and Three Days Of The Condor.

However, he reportedly turned the role down as he wasn't being offered enough money, and the unknown Christopher Reeve stepped in and proved iconic. We'd have loved to have seen a Redford Superman, but were very happy when he finally found his way into a superhero movie with his role as Alexander Pierce in Captain America: The Winter Soldier.

7 WORSE: GAL GADOT AS FAORA-UL

Gal Gadot won the hearts of fans when she first appeared as Wonder Woman in Batman V Superman: Dawn Of Justice, and that love increased even more when her solo movie proved to be a culturally important event in 2017. But things could have been very different if she had taken a role she was offered in 2011: Faora-Ul, General Zod's right hand woman in Man Of Steel!

At the time, she was pregnant and couldn't take the role and we think that was for the best. If she'd played a (relatively) minor henchman in that film there's no way she'd have been considered for the much bigger role of Diana Prince in the sequel and the world wouldn't have been treated to her brilliant portrayal of one of DC's iconic Trinity.

6 BETTER: WILL SMITH AS CLARK KENT/SUPERMAN

In 2008, during the press rounds for his role as the alcohol-dependant screw-up superhero Hancock, Will Smith revealed that he had been offered the role of Clark Kent in Superman Returns a few years earlier. He decided against it, though, as in the late '90s he played Jim West in Wild Wild West and emerged believing he couldn't again play a traditionally white character after the movie was critically mauled.

It's a depressing sign of the times that he felt that way and certainly there weren't the same issues with race-swapping his character Deadshot in 2016's Suicide Squad. We reckon the world could be more receptive these days and the idea of the uber-charismatic Smith playing Superman is certainly intriguing.

5 WORSE: CHRISTIAN BALE AS CLARK KENT/SUPERMAN

In 2003, before Batman Begins and Superman Returns made their way to the big screen, Wolfgang Petersen was developing a Batman Vs Superman movie. He met with two actors for the Superman role; one was the previously mentioned Josh Hartnett, who said no. The other was none-other-than Christian Bale, who would of course go on to play Batman in The Dark Knight Trilogy!

The movie was scrapped, but it's intriguing to imagine what Bale would have brought to the role. He's usually so intense and brooding in his films, but perhaps he could have brought some unexpected lightness to Clark Kent? Whatever the case, we would have been deprived of his amazing Batman portrayal if this had been brought to fruition, and that just simply wouldn't do!

4 BETTER: AMY ADAMS AS LOIS LANE (IN SUPERMAN RETURNS)

Amy Adams has now played Lois Lane in three DCEU films: Man Of Steel, Batman V Superman and Justice League. Winning the role of Lois was actually the culmination of a long journey for Adams, who had previously auditioned to her in two previous projects! In 2002 she screen tested with Matt Bomer for Superman: Flyby and she then auditioned a few years later for Superman Returns as well.

The Lois role in that film went to Kate Bosworth, whose lukewarm portrayal didn't win over many fans or critics, so it's not hard to imagine that the excellent Adams would've been a better choice even back then in 2006. Adams, incidentally, had another Superman connection: she appeared in a 2001 first season episode of Smallville playing a 'meteor freak' of the week!

3 WORSE: CONNIE NIELSEN AS LARA LOR-VAN

Danish actress Connie Nielsen has played Queen Hippolyta, Wonder Woman's mother and leader of the Amazons on the Island of Themyscira, in two movies: 2017's Wonder Woman and Justice League. However, she was previously rumored to have been offered the role of another maternal figure to a DC hero: Lara Lor-Van, Superman's Kryptonian mother in 2013's Man Of Steel.

That role was eventually played by Ayelet Zurer and was fairly minor in the grand scheme of things, so we reckon it's better that Nielsen wound up playing the much more important role of Hippolyta. She will reprise the role in 2020's Wonder Woman 1984 and we'd expect to see her in some other DCEU efforts as well.

2 BETTER: JOAQUIN PHOENIX AS LEX LUTHOR

Before signing on to play the Clown Prince Of Crime in Todd Phillips' upcoming Joker movie, three time Academy Award nominee Joaquin Phoenix was offered three other big superhero movie roles. Marvel approached him about playing Bruce Banner/Hulk in The Avengers but the role eventually went to Mark Ruffalo.

They then came very close to convincing him to sign on for Doctor Strange. DC/Warners also offered him the chance to play Lex Luthor in Batman V Superman, but he turned them all down because he wasn't sure he'd be able to make the acting compromises required to take part in such huge scale blockbusters. It was a pity, as there is no doubt in our minds that a Phoenix Luthor would've been infinitely better than Jesse Eisenberg's version!

1 WORSE: SEAN PENN AS JOR-EL

Russell Crowe played Jor-El, Superman's Kryptonian father, in Man Of Steel and his performance during the opening Krypton-set portion of the film was undoubtedly one of its strongest elements. Clive Owen was considered for the role before Crowe, as was Sean Penn, who reportedly was offered the part and turned it down.

Perhaps it was because he isn't a fan of superhero movies; he said in a 2015 interview that he believes it's a shame that Hollywood doesn't make more films that aren't 'tied to such packaged, childlike things'. He said he likes superhero movies if they're well made, and asserted that some are, but said he wasn't keen to star in one. That's as good a reason as any for us to believe he wouldn't have been as good as Crowe in the role of Jor-El!