How about when Ferris calls out the Head Waiter, despite the fact that he is lying about who he is.
Ferris and Cameron making Mr. Rooney think he just told Sloane's father to "kiss [his] big ol' white butt."
A Moment of Awesome for both Cameron and Ferris: first Cameron, who's normally terrified of his father, destroys the Ferrari and vows to stand up to his father for the first time in his life, then Ferris, when we realize that this appears to have been The Plan all along.
When Jeannie catches what she fears is a rapist or burglar in her house (actually Mr. Rooney), her immediate response is to kick him in the mouth not one, not two, but three times before running up the stairs and calling the police. And then she uses the intercom to talk to Rooney from her bedroom.
Jeannie, over the intercom: Excuse me. If whoever's in the house is still in the house, I'd like you to know that I have just called the police. If you have any brains whatsoever, you'll get your ass out of my house real quick. I'd also like to add that I have my father's gun. And a scorching case of herpes.