7. Tom Cruise As Iron Man
Not a terrible casting on paper, considering the actor's profile, and the star quality he would have potentially brought to the franchise, but that would ignore a great big factor that should have stood against Cruise. The key here is that Robert Downey Junior is very much like Tony Stark both men have suffered addiction and broken bodies and minds in the past, but neither let it really affect their indomitable spirits or their effortless charisma. Tom Cruise on the other hand would have played the character with too much irredeemable smarm, struggling to convince of the charm in Stark's snark (though for a while there was some promise in his Magnolia performance.) Perhaps he's just too nice. Plus despite his Hollywood star power, it remains hard to shake off the underlying feeling that Tom Cruise is just quite creepy. He is not the "people's champion" sort of actor like Downey Jnr, who could and would be forgiven for just about everything, and there's no way he would have authentically conveyed the vulnerable side of the character.