9. Michael Keaton - Bruce Wayne - Batman (1989)
Before the internet was even around and people could turn their thoughts into incoherent, capital-letter based rants in the comments sections of various webpages, fanboys still found ways to rally against whatever it was they didn't feel like enjoying at the time. One such rally came as a result of the announcement of Michael Keaton's bizarre casting in the role of Gotham billionaire Bruce Wayne, simply because - at the time - he was known purely for his comedic turns. Guess what happened? Fans sent 50,000 letters (yes - they actually wrote them out by hand and mailed them in their spare time and everything) to Warner Bros. asking them to reconsider their decision. 50,000! That's the same number of signatures that have been amassed thus far in the anti-Bat Affleck campaign. Alas, when Keaton finally showed up on screen, everybody said: "Oh, okay. Sorry about that. You were good as Batman." Oh, world.