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!

Homer: Aw, twenty dollars? I wanted a peanut!
Homer's Brain: Twenty dollars can buy many peanuts.
Homer: Explain how!
Homer's Brain: Money can be exchanged for goods and services.

You know, you remind me of a poem I can't remember, and a song that may never have existed, and a place I'm not sure I've ever been to.

Grampa

Wow, now I see why they call you Miss Hoover. You must have been vacuuming for an hour.

Bart

Horst: (Sinister) Okay, Mr. Burns, you win. But beware. We Germans aren't all smiles and sunshine.
Mr. Burns: (Sarcastic) Oooh, the Germans are mad at me. I'm so scared! Oooh, the Germans! (Hiding behind Smithers) Uh oh, the Germans are going to get me!
Horst: Stop it!
Man: Stop, sir.
Mr. Burns: Don't let the Germans come after me. Oh no, the Germans are coming after me.
Man: Please stop the "pretending you are scared" game, please.
Horst: Stop it! Stop it!
Mr. Burns: (Pause) No! They're so big and strong!
Man: Stop it.
Horst: Stop it, Mr. Burns.
Man: Please stop pretending you are scared of us, please, now.
Mr. Burns: Oh, protect me from the Germans! The Germans--
Horst: Burns, Stop it!

Mr. Burns: Oh, and one more thing: you must find the jade monkey before the next full moon.
Smithers Actually sir, we found the jade monkey. It was in your glove compartment.
Mr. Burns: And the road maps, and ice scraper?
Smithers: They were in there too, sir.
Mr. Burns: Excellent! It's all falling into place...

Just because I don't care doesn't mean that I don't understand.

Homer

Bones heal, chicks dig scars, and the United States of America has the best doctor-to-daredevil ratio in the world.

Lance Murdoch

Behold, the greatest breakthrough in labor relations since the cat-o-nine-tails!

Mr. Burns

Homer: Marge, where's that... metal... dealy... you use to... dig... food?
Marge: You mean a spoon?
Homer: Yeah yeah yeah!

Son, a woman is a lot like a... a refrigerator! They're about six feet tall, 300 pounds. They make ice, and um Oh, wait a minute! Actually, a woman is more like a beer. They smell good, they look good, you'd step over your own mother just to get one! But you can't stop at one, you wanna drink another woman!

Homer

(After Homer rejects other names for boys based on rhyming nicknames)
Marge: What about Bart?
Homer: Let's see. Bart, dart, cart, e-art. Nope can't see any problems with that.
(Missing fart due to only 4 fingers)

The Simpsons Quotes

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!

Homer: Aw, twenty dollars? I wanted a peanut!
Homer's Brain: Twenty dollars can buy many peanuts.
Homer: Explain how!
Homer's Brain: Money can be exchanged for goods and services.