10. Hugh Jackman Over Dougray Scott (X-Men)
Though it's impossible to think about nowadays, Hugh Jackman actually wasn't the first choice to play Wolverine in Bryan Singer's ground-breaking original X-Men movie.
Singer originally envisioned Russell Crowe for the part, but he turned it down and instead recommended his pal Jackman. Singer, however, ignored his advice and offered the part to the more established Dougray Scott, who accepted.
Fate intervened, though, as Scott was forced to withdraw several weeks after principal photography had already begun due to scheduling conflicts with the delayed Mission: Impossible II.
Singer quickly cast Jackman as his replacement, and though the casting of the fairly unknown Jackman sparked a lot of scepticism online, almost 20 years later it's tough to imagine Scott taking the role to the same brilliant places.