When trying to take the fishing boat, McMurphy gives the captain his number. An acute complains that they shouldn't be rushing off, and McMurphy replies by rhetorically asking: "Are we just going to wait until he finds out that that number I gave him is a brothel's? Let's get moving!
And of course the final scene, where Chief rips out the water fountain, like McMurphy had tried but failed to do, smashes through the window, and escapes the hospital, becoming the title character.
Billy standing up to Ratched after she finds him in bed with a prostitute— and notice, for once he doesn't stutter. Too bad she won't let him keep his victory, though, but it's very impressive that he did it.
Ratched: Aren't you ashamed?
Billy: (breaking out in a genuine, shit-eating grin) No, I'm not.