I know Michael Keaton killed it as Riggan, but following the movie's whole theme about being washed up who else would you have cast for Riggan? My picks are as follows:
Tom Berenger
Nicolas Cage
John Cusack
Brendan Fraser
Christopher Reeve (if he were still alive and didn't have the accident)
The role of Riggan required an actor who can give a performance that would be in automatic contention for Best Actor, but who had a past association with a superhero role.
That makes for a pretty short list! I suppose you could put Robert Downey Jr. on it as well as Keaton, but his bosses at Marvel might object and I doubt he'd want to admit he was old enough for the role. Michael Fassbender might have the talent and the underlying hint of crazy, but he's just too young.
“Seventy-seven courses and a regicide, never a wedding like it!
Jim Carrey.
shareNicolas Cage 100%
shareThis film would have been great if it were handed to Nic Cage. He would have restored his flailing career much sooner.
shareSylvester Stallone could have done it, but it would need to be retooled to more match his Rambo/Rocky history. One of the reasons this film is so amazing is because of the casting with Keaton doing a warp version of his own history.