Fight Club (1999)
Brad Pitt and Edward Norton
I’m going to have to break a couple rules to talk about this one. In David Fincher’s gritty underground masterpiece ‘Fight Club’, the script called for Edward Norton’s character to throw a half-assed jab at Brad Pitt’s shoulder. However, right before the take, Fincher pulled Norton aside and whispered “hit him in the ear.”
The result was the completely genuine line from Pitt, “You hit me in the ear?! Why the ear?!” Don’t tell anyone I told you this.