Which movies would you liked to have seen a change of actor in the lead role & who would you have cast instead?

Yeah, a fair amount if not the majority of actors we see in the final film were not the first choice. Clint Eastwood has revealed he turned down two major roles in the past. Confirmation. Can’t imagine him in either role so probably just as well. So yeah, if you had been wielding the directors wand, what changes would you have made? Purely hypothetical of course, I mean you never know how the performance would have changed the movie. Nevertheless it’s fun to imagine. Lights camera action!!!