Homer: Welcome to the Internet, my friend. How can I help you?
Comic Book Guy: I'm interested in upgrading my 28.8 kilobaud Internet connection to a 1.5 megabit fiber optic T-1 line. Will you be able to provide an IP router that's compatible with my token ring ethernet LAN configuration?
[The two look at each other awkwardly for a few seconds.]
Homer: Can I have some money now?

Groundskeeper Willie: Yeah, I bought your mutt, and I 'ate him. I 'ate his little face. I 'ate his guts. And I 'ate the way he's always barking, so I gave him to the church.
Bart: Oh, I see. You hate him, so you gave him to the church.
Groundskeeper Willie: Aye, I also 'ate the mess he left on me rug.

[Two bandits have stolen the grease Homer is collecting to sell]
Homer: Hey, hey, you're taking our grease!
Grease Bandit #1: It's our grease now. [Takes away Homer's shovel and hits him over the head with it.]
Homer: Daaah!
Grease Bandit #2: We run the grease racket in this town.
Homer: Hey, that's my shovel.
Grease Bandit #1: We also run the shovel racket.

Lisa's Date with Density - S8-E7
Mr. Largo: Miss Simpson, do you find something funny about the word "tromboner?"
Phaneron
The Springfield Files - S8-E10
Leonard Nimoy: The following tale of alien encounters is true. And by true, I mean false. It's all lies. But they're entertaining lies. And in the end, isn't that the real truth? The answer is no.
Phaneron
Marge vs. the Monorail - S4-E12
Leonard Nimoy: I'd say this vessel could do at least warp five.
Mayor Quimby: And let me say, may the Force be with you.
Leonard Nimoy: Do you even know who I am?
Mayor Quimby: I think I do. Weren't you one of the Little Rascals?

The Wettest Stories Ever Told - S17-E18
Flanders: We Puritans have no place for drunkenness, or colorful clothes, or dreaming or poetry. So if you write a sonnet, keep it under your bonnet. Oh no! That was a poem. [Flogs himself].
Phaneron
Springfield Connection - S6-E23
[Hans Moleman is about to be executed and Homer has eaten his last meal.]
Reverend Lovejoy: Alright Hans, time to go.
Hans Moleman: But he ate my last meal.
Reverend Lovejoy: If that's the worst thing that happens to you today, consider yourself lucky.
Hans Moleman: Are you really allowed to execute people in a local jail?
Reverend Lovejoy: From this point on, no talking.

Jimbo: Dude, you kissed a girl! That is so gay.
Dean: Hello, that sounds like a pig fainting.
Brother From Another Series - S8-E16
Sideshow Bob: You do know I had a...problem with trying to...kill people?
Cecil: [sarcastic] Goodness, I had no idea! For you see, I have been on Mars for the last decade, in a cave, with my eyes shut and my fingers in my ears.
Sideshow Bob: Touché, Cecil.
Homer vs. the 18th Amendment - S8-E18
Rex Banner: You're out there, Beer Baron, and I'll find you.
Homer Simpson: [faintly from the horizon.] No, you won't!
Rex Banner: Yes, I will.
Homer Simpson: Won't!
Squeaky Voiced Teen: We're out of Secret Sauce. Go and put this mayonnaise out in the sun.
Homer: I won't lie to you Marge... Well, good night.
Weekend at Burnsie's - S13-E16
Otto: They call them fingers, but I never see them fing. Oh, there they go.
Answer: I'm not sure if this is the one you're thinking of, but an episode of "Ray Bradbury Theatre," called "A Sound of Thunder," dealt with a similar matter: a group of hunters travel back in time to hunt dinosaurs, only to find things have changed when they get back because someone stepped on a butterfly.
Xofer