Watching Jaws today and this scene is so good: the police chief is sitting at the dinner table in anguish cus his negligence has caused a boy's death. His young son is mimicking his every move. He notices, lightens up, asks for a kiss.
Boy: why?
Chief: because I need it.

It's such efficient characterisation. This one scene alone is sufficient to tell you all you need to know about the chief. He's a responsible man who takes his duties seriously, both at work and in the home.

Such a stellar script:

Chief's Wife: Martin hates water. He never swims. I suppose it's a childhood thing. There must be a medical term for it.

Chief: drowning.