Ferris (Matthew Broderick) talks directly to the camera, a common technique in the movie.

Ferris: How can I possibly be expected to handle school on a day like this?

This is my ninth sick day this semester. It's pretty tough coming up with new illnesses. If I go for 10, I'm probably going to have to barf up a lung, so I better make this one count.

Ferris: The key to faking out the parents is the clammy hands. It's a good nonspecific symptom; I'm a big believer in it. A lot of people will tell you that a good phony fever is a deadlock, but, uh ... you get a nervous mother, you could wind up in a doctor's office. That's worse than school. You fake a stomach cramp, and when you're bent over, moaning and wailing, you lick your palms. It's a little childish and stupid, but then, so is high school.

School secretary Grace (Edie McClurg) describes Ferris to Principal Rooney (Jeffrey Jones).

Grace: Oh, he's very popular, Ed. The sportos, the motorheads, geeks, sluts, bloods, wastoids, dweebies, (expletive) — they all adore him. They think he's a righteous dude.

Ferris' sister, Jeanie (Jennifer Grey): Maybe I'm overreacting. Maybe Ferris isn't such a bad guy. After all, I got a car, he got a computer. But still, why should he get to do whatever he wants, whenever he wants? Why should everything work out for him? What makes him so (expletive) special?

Ferris: The question isn't "what are we going to do?" The question is "what aren't we going to do?"

Cameron (Alan Ruck): (singing to the tune of Go Down Moses) When Cameron was in Egypt's land, ... let my Cameron go."

Ferris: I do have a test today ... It's on European socialism. I mean, really, what's the point? I'm not European. I don't plan on being European. So who gives a crap if they're socialists? They could be fascist anarchists; it still doesn't change the fact that I don't own a car.

Teacher: Bueller? Bueller? Bueller?

Ferris, Cameron and Sloane (Mia Sara) are trying to dine at an exclusive restaurant, and the maitre d' has become suspicious.

Cameron: OK Ferris, can we just let it go, please?

Sloane: Ferris, please. You've gone too far. We're going to get busted.

Ferris: A: You can never go too far. B: If I'm gonna get busted, it is not gonna be by a guy like that.

Ferris and Cameron are leaving Cameron's father's vintage Ferrari at a parking garage.

Garage attendant: You guys got nothing to worry about, I'm a professional.

Cameron: A professional what?

Jeanie has been arrested in her quest to prove Ferris is not sick and is waiting at the police station for her parents.

Jeanie: In a nutshell: I hate my brother.

Boy in police station: That's cool. Did you blow him away or somethin'?

Ferris: Life moves pretty fast. If you don't stop and look around once in a while, you could miss it.

Source: Imdb.com