Name a single movie scene that justifies an actor's entire career

[Brother Buzz]

29. The Five Easy Pieces Diner Scene is where we see the real Jack Nicholson

Bobby (Jack Nicholson) wants plain toast, which isn't on the menu
Bobby: I'd like an omelet, plain, and a chicken salad sandwich on wheat toast, no mayonnaise, no butter, no lettuce. And a cup of coffee.
Waitress: A #2, chicken salad sand. Hold the butter, the lettuce, the mayonnaise, and a cup of coffee. Anything else?
Bobby: Yeah, now all you have to do is hold the chicken, bring me the toast, give me a check for the chicken salad sandwich, and you haven't broken any rules.
Waitress: You want me to hold the chicken, huh?
Bobby: I want you to hold it between your knees.