When you look at iconic films like Batman, Indiana Jones, Blade Runner and countless others, it's almost impossible to disassociate them with the people playing them.
There's literally thousands of stories about actors almost catching famous roles, but we thought we'd pick seven of the most utterly unbelievable.
You couldn't imagine anyone but Alicia Silverstone as Cher Horowitz, right? There's no way anyone but Alan Rickman could be Snape also, right?
Wrong. Take a look at this.
7. TIM ROTH - Severus Snape in 'Harry Potter'
Veteran British actor Tim Roth was the most likely choice to play Severus Snape in the Harry Potter franchise. According to legend, it was a choice between Severus Snape or General Thade in Tim Burton's remake of Planet of the Apes. Roth decided that since Planet of the Apes was a more significant role for him, he went for that. And we all know how that film turned out. Yeeshk. Bad call, Tim Roth.
6. DANIEL DAY LEWIS - Aragorn from 'Lord of the Rings'
Yup, DDL was going to be the heir of Isildur. Or maybe not. Peter Jackson famously lobbied Day-Lewis on numerous occasions to take up the mantle of Aragorn - but to no avail. Day-Lewis has starred in just 20 films in his 35-year career, so we're guessing the idea of signing on for three films wasn't his particular bag. That's not to detract from Viggo Mortensen, mind. He was fantastic in the role and we genuinely couldn't see anyone else in it.
5. BRAD PITT - Jason Bourne from 'The Bourne Identity'
The Pittster didn't exactly do too badly by turning down Jason Bourne. The actor was offered two roles - one in this and the other in Spy Game, alongside Robert Redford. Put yourself in his shoes. You can work with one of the most well-known actors of any generation and have it directed by an acclaimed director, e.g. Tony Scott. Or you can do a film done by the guy that did Swingers. We can't fault Pitt taking the safer option here, and to be honest, Spy Game's an underrated gem.
4. SARAH MICHELLE GELLAR - Cher from 'Clueless'
As if! Yes, Buffy was almost going to play Cher Horowitz in 90's classic Clueless. However, the young actress was then working on long-running soap opera All My Children and was forced to turn down the role. Gellar, as we know, would go on to star in other 90's classic Buffy The Vampire Slayer and became the heroine of many a young woman. We'd like to see a crossover where Buffy Summers turns up in Beverly Hills High and starts beating the shit out of people. We'd watch it.
3. REESE WITHERSPOON - "Amazing" Amy in 'Gone Girl'
Yes, everyone's favourite ice queen murderess was almost played by Elle from Legally Blonde. In fact, Reese Witherspoon was even a producer of the smash-hit thriller. Director David Fincher sat Witherspoon down and convinced her why she wasn't right for the part. Obviously, it worked because we really couldn't imagine anyone but Rosamund Pike slicing Barney Stinson's throat. She really nailed it.
2. SYLVESTER STALLONE - Kal-El / Superman / Clark Kent in 'Superman'
Yes, we all may be aware that Nicolas Cage was in the running for Superman in the 1990s, but did you know Sly Stallone was nearly gonna play by the Last Son of Krypton? Richard Donner's Superman film, all the way back in 1978, was looking for all sorts to play Supes and had a lengthy casting process. Apparently, NEIL DIAMOND was even in the running. Sylvester Stallone came right down to the wire to don the red cape, but when Marlon Brando signed on to play Jor-El, Superman's father, he put the kybosh on the whole thing. Brando specifically ordered the producers to not cast Stallone. Imagine Stallone as Superman? We can't.
1. LIAM NEESON - Abraham Lincoln in 'Lincoln'
It's crazy to think, but there are people young enough now who don't remember a time when Liam Neeson was actually a serious actor in serious roles. Neeson almost an Oscar for playing Oskar Schindler in Spielberg's Schindler's List and was the director's favourite to play Honest Abe in the long-gestating biopic. Neeson had signed on to play the President A DECADE before production started, with the Ballymena man carrying out over four years of research and preparation. And then in saunters Daniel Day-Lewis with his method acting and takes the role. Or not, as the case may be. Neeson pulled out of the role after a poor script-read. Neeson's wife, Natasha Richardson, had died a month prior to this and the actor felt that he simply didn't want to take the role. Given that kind of loss, it's totally understandable.