Principal Skinner: Willie, go into the vent and get him.
Groundskeeper Willie: What!? Have ye gone waxy in yer beester? I canna fit in the wee vent, ye croquet-playin' mint-muncher!
Principal Skinner: Grease yourself up and go in, you guff-speaking work-slacker.
Groundskeeper Willie: Ooh. Good comeback.

Agnes: (From downstairs) Seymour, your friend Bart is here.
Principal Skinner: I know, mother!
Agnes: Seymour, do you want me to tell you when it's 7:30?
Principal Skinner: No, mother!

Homer: So, Mr. Malloy, it seems that the cat has been caught by the very person who was trying to catch him.
Principal Skinner: How ironic.

Good Lord! My Stormin' Norman commemorative plates stolen! Again

Marge: I don't think the guns are a good idea!
Homer: Marge! We're responsible adults a--
(Gun shot)
Moe: Whoops!
Homer: And if a group of responsible adults can't handle firearms in a responsible way--
(Gun shot)
Captain McCallister: Sorry!
(gun shot)
Principal Skinner: Uh oh!
(Gun shot)
Moe: Me again...
(Gun shot)
Bart: Sorry.

Principal Skinner: And here is a special award to the children who obviously didn't have any help from their parents, Lisa Simpson and Ralph Wiggum.
Ralph: (With a plastic bag that says "Idaho" on it) I'm Idaho!
Principal Skinner: Sure you are!

Bart: Each parking space is a mere one foot narrower, indistinguishable to the naked eye. Therein lies the game.
Millhouse: I fear to watch...yet I cannot turn away!
Principal Skinner: Blasted woman, you parked too close, move your car!
Mrs. Krabappel: I'm in the lines. You got a problem, go tell your mama.
Principal Skinner: Oh, don't worry, she'll hear about this!

Eat my shorts, young man!

Damn! They're very slowly getting away!

Principal Skinner: Pull, Willie, pull!
Groundskeeper Willie: I'm doin' all the pulling, you blouse-wearing poodle-walker!

Hello, Simpson. I'm riding the bus today because Mother hid my car keys to punish me for talking to a woman on the phone. She was right to do it.

(Homer, Apu and Skinner, with stubble on their faces, are in the recording studio)
Homer, Apu, Skinner: (singing off-key) For all the latest medical poop,
Call Surgeon General C. Everett Koop.
Poo poo pa-doop...
Apu: This is worse than your song about Mr. T.
Homer: I pity the fool who doesn't like... he. And where's Barney?
Skinner: Oh, he's with his new girlfriend, the Japanese conceptual artist.
(Barney and his girlfriend walk in, and Barney inserts a demo tape into a recorder)
Barney: Barbershop is in danger of growing stale! I'm taking it to strange new places!
(On the recorder)
Barney's Girlfriend: Number eight... (Barney belches) Number eight... (Barney belches) Number eight... (Barney belches)

The Simpsons Quotes

The Constitution? I'm pretty sure the Patriot Act killed it to ensure our freedoms.

Bart

Homer: (Wearing glasses) The sum of the square roots of any two sides of an isosceles triangle is equal to the square root of the remaining side!
Man: (From inside a bathroom stall.) That's a right triangle, you idiot!
Homer: D'oh!