10 Ridiculous Comic Book Castings (That Actually Totally Worked)

5. Robert Downey Jr. - Tony Stark (Iron Man)

Why It Was Ridiculous: Robert Downey Jr? The guy who played that Aussie reporter in Natural Born Killers? The Ally McBeal guy? Or as most people will remember him for a good deal of the late 1990s and early 2000s, that strung-out drug addict? Though the idea of a substance abuser playing one on screen makes sense from a performance standpoint, one can't possibly imagine why a major studio would take a gamble on such a flight risk, especially considering the world Marvel were planning to build. Sure, Downey had been on the mend for a number of years, but was the risk really worth it? The Result: Well, yes. Downey absolutely killed the role, his cocky demeanour playing perfectly as the arrogant, alcoholic billionaire, and there's no doubting that his real-life substance issues made him more believable as the flawed character. He ended up earning an estimated $50 million for The Avengers alone, and with Iron Man 3 being the highest-grossing film of 2013, it's clear that Downey's name alone is box office dynamite.