It's something of a miracle when a movie doesn't turn out to be an utter disaster. With all the moving parts involved in making a motion picture, it's incredible when any movie gets completed, whether or not it fulfills the director's vision.

The magic of selecting the right behind-the-scenes team is difficult enough. Then there's casting and making sure all the actors have good chemistry. One miscast role can make the difference between a "decent" flick and an abysmal one.

In many of your favorite films, a last-minute casting decision, re-shoot, or happy accident led to an unforgettable performance we might not otherwise have seen,