For me I think it was Jack Black in King Kong. I just wasn’t prepared for Jack Black being in a more serious role.
Kind of a cliche answer now, but at the time, everyone was shocked by Heath Ledger’s casting as Joker.
Similarly, I was initially skeptical when Robert Pattinson was announced for The Batman. But I thought he did a fantastic job!
I never would have expected John Malkovich to want to do the movie ‘Being John Malkovich’. It was such a crazy movie, and he is such a serious actor
Oh, I have a better one; Angela Lansbury in ‘The Manchurian Candidate’. As far as I know, the only time she has played a villain. And she was fantastic
Kevin James as a violent Neo Nazi in ‘Becky’.
And he was actually really good in it!
Robin Williams in One Hour Photo. He did such an amazing job but it was just so unexpected at first to get over that he was doing a serious role that was a psychopath.
Mike Myers in Inglorious Basterds just always stood out to me as being, weird. Supposedly Adam Sandler was supposed to play the Bear Jew, and Simon Pegg was supposed to play the British Spy masquerading as the German officer. (Michael Fassbender). So the movie could have been quite “diverse” in terms of casting.