Most of the time casting directors get it right on the money - could you imagine Ace Ventura as anyone but Ace Ventura? Or all of those Tim Burton films starring anyone but Johnny Depp? Exactly.
But on the odd occasion, they seem to blinded by star power, executive orders or a bout of madness, as they pick actors for roles that really don't make any sense at all, thus ruining potentially good films.
11. Owen Wilson - Behind Enemy Lines
On the back of appearing in comedies Shanghai Noon, Meet the Parents and Zoolander, Owen Wilson wanted to showcase his serious acting chops, so he took on the lead of a US Navy flight officer in action movie Behind Enemy Lines.
Unfortunately his reputation as a comedy actor, plus his soft-spoken, laid back attitude meant that he couldn't be taken seriously as a naval pilot in the middle of a warzone.
10. Jake Gyllenhaal - Prince of Persia: The Sands of Time
A film based on a video game - they're always cinematic gold, right? Jake Gyllenhaal took on the role of Persian Prince Dastan in the action fantasy which Disney was eyeing-up as 'the new Pirates of the Caribbean'.
Despite grossing over $300 million, the American Gyllenhaal playing a Persian in a film set in Persia (now known affectionately as Iran) caused more issues about whitewashing, plus his dull performance didn't help things either and we have yet to hear anything about a sequel.
9. George Lazenby - On Her Majesty's Secret Service
Who will you pick to replace Sean Connery as James Bond - the first actor to portray 007 and an incredibly hard act to follow?
Australian model George Lazenby of course! The role in On Her Majesty’s Secret Service was Lazenby's first acting role as he gave a really uninspiring and dull performance as 007.
Lazenby decided that he wouldn't bother playing Bond again after falling out with the producers, although more recently, Lazenby's performance has been viewed in a more positive light and OHMSS is now regarded as one of the best films in the Bond series.
8. Kevin Costner - Robin Hood: Prince of Thieves
One of England's most famous folklore figures was brought to the big screen in 1991 by Oscar-winner Kevin Costner.
Playing the bow and arrow-wielding Nottingham outlaw, Costner brought his considerable acting skills, but not his accent skills, as he played Robin Hood as an apple pie-eating, stars and stripes-saluting American.
Aided by fellow Americans Christian Slater and Morgan Freeman, the only main character to be played by an Englishman was the villainous Sheriff of Nottingham by Alan Rickman, who won the Best Supporting Actor BAFTA, while the rest of the film went down in a flaming pile of rubbish, spearheaded by Costner's performance.
Except for that Bryan Adams song, that was pure magic.
7. Vince Vaughn - Psycho (1998)
After his Best Director Oscar nomination for Good Will Hunting, Gus Van Sant wanted to prove he was a brilliant director, by doing a shot-for-shot remake of the Alfred Hitchcock horror classic Psycho.
Many questions arise about this sorry situation, but a significant one is the casting of Vince Vaughn as the unhinged Norman Bates.
Vaughn, who had impressed a couple of years earlier with his role in Swingers, struggled to repeat Anthony Perkins' terrifying performance and we got a comedy actor desperately trying to play it straight while copying one of cinema's finest performances - needless to say it didn't work.
6. Rosie O'Donnell - The Flintstones
Back in the mid-90s, someone made the decision that The Flintstones needed a live-action version, and set about ruining many childhoods with that idea.
To play the role of Barney Rubble's slender wife Betty, plus-sized actress and loudmouth Rosie O'Donnell was chosen, because she was able to do Betty's high-pitched laugh... and no other reasons.
Predictably, not many people were positive about O'Donnell's performance, and she won the Worst Supporting Actress Razzie for her troubles.
5. Topher Grace - Spider-Man 3
Who did they chose to cast to play the big-toothed black-suited anti-Spidey? Eric Foreman from That '70s Show of course.
Topher Grace's turn as Eddie Brock/Venom wasn't helped by Raimi being forced to crowbar another villain into the already dense Spidey story, but his cocky approach wasn't what loyal Spider-Man fans were after in Venom, and the whole film went down like a giant damp squib.
4. Sofia Coppola - The Godfather Part III
Actual good actress Winona Ryder was all set to play Michael Corleone's daughter in The Godfather Part III when she was taken ill, instead of casting a similarly talented actress to replace her; Francis Ford Coppola picked his daughter Sofia instead.
While the third Godfather film was seen as a big step down from the first two movies, critics zeroed-in on Sofia's performance, and she won the Razzie Awards for Worst Supporting Actress and Worst New Star of 1990.
Sofia Coppola only starred in a few more films (including getting another Worst Supporting Actress nomination for Star Wars: The Phantom Menace) and has since forged a more successful career as a screenwriter and director.
3. Denise Richards - The World Is Not Enough
The producers were obviously trying to find the most '90s actress they could think of to be Bond girl in 1999's The World Is Not Enough.
Tiffani Amber Thiessen and Alicia Silverstone must have been busy, because they cast Denise Richards to play a nuclear physicist, and everyone rejected the idea, because nuclear physicists should be bookish and wear glasses and have bad hair, not a hot woman unconvincingly using scientific terms.
Also, she was named Dr. Christmas Jones so the screenwriters could have some fun with festive/sexual puns, which were:
"I thought Christmas only came once a year."
"I've always wanted to have Christmas in Turkey"
"Is it about time to unwrap your present?"
2. Colin Farrell - Alexander
In Oliver Stone's 2004 biopic of the all-conquering Alexander the Great, Colin Farrell was cast as the Ancient Greek and told to come up with an accent that was suitable to the man born in the Ancient Greek kingdom of Macedon.
What Farrell decided would suit Alexander the Great was a Guinness-supping, leprechaun-chasing traditional Irish accent, obviously.
As a result of Alexander's Irish accent, his co-stars, including Angelina Jolie, Jared Leto and Val Kilmer, were forced to put on their own Irish accents in order to cover up for Farrell's Irish accent, making the film seem like it was set in Dublin rather than Ancient Greece.
Also, he looked dumb with that blonde wig.
1. Hayden Christensen - Star Wars: Episode II & III
Coming off the back of an enormously-hype and crushingly-disappointing Stars Wars: Episode 1 - The Phantom Menace, George Lucas went with Hayden Christensen for the role of Anakin Skywalker in the follow-up films.
Lloyd's performance as a nine-year-old future Darth Vader was criticised so much that he quit acting; enter unknown 19-year-old Canadian actor Hayden Christensen, who took on the role, and George Lucas' horrible script, for the subsequent two movies.
While Darth Vader is powerful, scary, power-hungry and capable of crushing his enemies with ease, Christensen played his pre-dark side Anakin Skywalker as a spoiled, petulant brat that lacks the menace that made Vader such a memorable and terrifying character.