Sir Sean could have made a fortune had he accepted a lucrative profit-sharing deal to play Gandalf in the Lord of the Rings series. But the normally canny Scot turned down the offer, saying he'd read the script and "never understood it". Ian McKellen would eventually play the wizard role.
Paltrow was James Cameron's first choice to play Rose in Titanic but turned it down. Claire Danes was also offered the role, but passed because she had just worked with Leonardo DiCaprio on William Shakespeare's Romeo + Juliet. Kate Winslet begged to be cast in the film and was.
Anne-Hath was originally given the lead in Knocked Up but pulled out when she discovered Judd Apatow intended to use footage of an actual child birth in the scene where her character has a baby. Katherine Heigl had no qualms about it and ended up securing her career-making role.
Pitt was lined up to play Jason Bourne in The Bourne Identity but pulled out to play another secret agent in Spy Game, opening the door for his Ocean's Eleven co-star Matt Damon. Bourne Identity director Doug Liman would eventually work with the Pittster on Mr and Mrs Smith.
Hannah turned down the role of Vivian because she thought it was "degrading for the whole of womankind. They sold it as a romantic fairytale when in fact it's a story about a prostitute who becomes a lady by being kept by a rich and powerful man". It also made Julia Roberts a huge star, of course, but good on Daryl for sticking to her guns.
Big Russ was offered the Wolverine role in the first X-Men but demanded too much money. Scottish actor Dougray Scott was then cast, but had to pull out when filming went over schedule on Mission: Impossible II. So Hugh Jackman stepped in, sticking around for two sequels and a prequel.
Matt had discussions with James Cameron about Avatar but could not accept the role of Jake Sully (eventually played by Sam Worthington) due to a scheduling conflict with The Bourne Ultimatum. "He was a gentleman about it," Matt shrugged later. "Clearly my not participating cost the film a lot."
Former indie star Jake also had the chance to muscle up and star in action epic Avatar. Instead, he chose... er, Prince of Persia. Big mistake. Avatar went on to be the biggest movie of all time, and put Sam Worthington at the top of Hollywood wish-lists. Prince of Persia was, well, Prince of Persia.
Roberts was lined up to be the female lead in Shakespeare in Love in the early 1990s but abruptly pulled out when Daniel Day-Lewis, her boyfriend at the time, refused to play the Bard. Some years later, Gwyneth Paltrow played the role and scooped an Oscar for her trouble.
Hackman originally owned the rights to The Silence of the Lambs and at one stage intended to play Hannibal "The Cannibal" Lecter. When he got cold feet, the film was offered to Sean Connery and Jeremy Irons. Both turned it down, allowing Anthony Hopkins to bag his Oscar-winning part.
Travolta was offered the role of Forrest Gump in Robert Zemeckis' picture but turned it down as did Bill Murray and Chevy Chase. Tom Hanks ended up playing the part and winning his second Oscar for it, beating Travolta, nominated the same year for Pulp Fiction, in the process.
Big Will was handed the Matrix script on a platter but promptly passed. "In the pitch, I just didn't see it," he says. "I would have absolutely messed up The Matrix... Keanu was smart enough to just let it be. Let the movie and the director tell the story and don't try and perform every moment." Hmm, backhanded compliment there?
Basic Insinct could have made Kelly Lynch a household name instead of a, "Who?.. oh, the one from Drugstore Cowboy?" But recent interviews claim Lynch turned down the role as it wasn't a balanced portrayal of bisexual women. She went on to star in lesbian film Three Of Hearts and The L Word. Kelly is married with kids, just in case you're wondering.
Ian Fleming had Grant in mind for the role of the superspy but Grant met the Dr No offer with a resounding... "no". At 58, he thought he was too old for the role, and also didn't fancy being tied to a film series. Grant starred in just three movies after that - wonder if Bond would have kept him going well past his pension?
Kidman won an Oscar for The Hours and was all set to reunite with director Stephen Daldry on The Reader. When the Australian star became pregnant, though, she swiftly withdrew, allowing Kate Winslet to get the role that won her the Oscar she had previously been denied five times.
Oh the irony - the future star of The Sixth Sense thought "playing a ghost would be detrimental to his career" so he declined to star in Ghost, a huge box office smash and career highlight of Patrick Swayze and Willis' then-wife, Demi Moore. Must have made for interesting pillow talk.
The Cage was pumped to play Randy "The Ram" Robinson in The Wrestler but pulled out over fears he would not have enough time to hone the necessary physique. His departure was good news for Mickey Rourke, who ended up with a Bafta, a Golden Globe and Iron Man 2.
Julia again. This time she was first choice for the real-life do-gooder in The Blind Side. But it turned into Sandra Bullock's very own Erin Brockovich when the "serious" role won Sandy her first Oscar. Meanwhile Roberts appeared in the atrocious Valentine's Day. Still, it was Sandy's turn, right?
Selleck was offered the role of Indiana Jones in Raiders of the Lost Ark but had to turn it down because he had already committed to appearing in TV show Magnum PI. With just three weeks to go, director Steven Spielberg persuaded George Lucas to cast Harrison Ford.
