5. Adam Sandler (Sgt. Donny Donowitz, Inglourious Basterds)

People were shocked enough that Tarantino cast his good buddy Eli Roth in a role in Inglourious Basterds, let alone one as meaty and crucial as "The Bear Jew" Donny Donowitz, yet the director's first choice was an even more left-field one, another of Tarantino's friends - Adam Sandler. Though Sandler has occasionally proven a deft dramatic performer - Punch Drunk Love, Reign Over Me - this would have been like nothing he had ever played before, a darkly funny yet twisted character who savours murdering Nazis. Though I have little doubt that Sandler would have pulled it off, we never got the chance to find out, because the actor's schedule on Judd Apatow's Funny People meant that he wasn't able to accept the part. Sandler has proven that in spite of his glut of awful films, he is a talented actor when paired with the right script and director - it's just that this doesn't happen very often. What a shame, even though Roth totally killed the role.