Great subtle moments in movies

[Triumph36]

Inspired by Rushmore's thread, except kind of the opposite. What's a terrific moment that you don't think most people are aware of?

The Big Lebowski has about 100, but my favorite is when Jackie Treehorn is talking to the Dude - Treehorn says, "People forget that the brain is the biggest erogenous zone.", and the Dude says - "on you, maybe." Perhaps I'm an idiot, but the implication to me was always that the Dude's [censored] was about the size of his head, which is a pretty hilarious joke.

Anyway, list better ones than that.