I think this is the end of the greyhound episode- Mr. Burns has a change of heart, and decides not to turn the 25 greyhounds into a fur coat, but ends up raising them to be champion race dogs. All of them win a championship and make Mr. Burns presumably even richer. As he stands with his new champs, the racetrack announcer says that he bets whoever gave those dogs up is kicking himself now. Cut to: the basement of the Simpson house. We see the shadow of Homer swinging back and forth, as if he has hanged himself. Marge walks down the stairs and gasps. Pan up to reveal Homer alive and well, holding onto a dangling lightbulb. “What’s the matter, Marge? You know batting at this lightbulb is the only thing that makes me happy now.”
How about the “Lord of the Flies” episode, right after all the kids have subdued the wild boar.
Lisa (paraphrasing): Look! This boar must have been eating the moss off this rock. We can do that too and survive to be rescued!
A moment passes as all the kids ponder the turn of events.
Cut to: A barbecue, with the wild boar turning on a spiggot over a fire. Only Lisa is stooping to licking moss off a rock. (Lisa: “Stupid savages!”)
And perhaps the first, best switcheroo: Homer (after failing to jump Springfield gorge) is awkwardly airlifted out of the canyon, loaded into an ambulance that takes off…and crashes into a tree. Homer’s stretcher then tumbles back out…and down into the canyon again.
I always love this bit from Cape Feare.
Bart’s on the boat heading down the river and is trying to escape from Sideshow Bob. He looks over the bow…alligators! He runs to the stern…electric eels! He runs back to the bow…“Oh, yeah…”, now he remembers that the bow was alligators again.
One of my favorite examples of an ironic gag was a well-written one in the final episode of Futurama. Fry wants to get new hands so he can play the Holophoner better to impress Leela. So he makes a deal with the Robot Devil- he gets Fry’s hands in exchange for the hands of another robot. When I saw this, I thought to myself, “Oh, it’s obviously going to be Bender,” since I think Bender had a plot going on too. The Robot Devil spins a giant wheel with the names of all robots to determine who hands Fry will recieve. Sure enough, it lands on Bender- before moving a little bit and landing on the Robot Devil. The Robot Devil regrets putting his own name on the wheel. (Ironically, this episode features a running gag in which Bender is attempting to figure out the defintion of the word “irony.”)
All the funnier of course, b/c in the first Treehouse of Horror in Season 2, Homer does the same thing, except that time there’s a mushroom cloud of lighter fluid that attracts Kang and Kodos for the first time…
…during which they do the whole Twilight Zone “cookbook” thing:
Lisa says: "They’re fattening us up…so they can eat us! Just look at this book I found:
<title reads>: “How to Cook Humans”
Kang blows off some just to reveal: “How to Cook For Humans”
Lisa blows off more dust: “How To Cook Forty Humans”
Kodos blows off more dust, which turns it into “How To Cook For Forty Humans”
And that’s it. Kodos scorns them by saying “You’ve made Cyrak the Prepared cry.” And then they dump them back on Earth for being rude guests. Goo-hay.
Someone (I presume Bart or Nelson) has stretched some piano wire across the road. Cut to Milhouse’s dad driving his convertible down the road. He’s holding a sub sandwich in the air, loudly ranting about he asked them to cut it in half, but they didn’t cut it in half.
The wire takes his arm off at the elbow.
It only almost fits the OP, and loses a lot without the delivery – but I have to mention the time Homer sent an angry letter to his boss, and then realized he needed to intercept it. And so he goes to the Post Office.
“Hello, my name is Mister Burns. I believe you have a letter for me?”
“All right, Mister Burns. What’s your first name?”
“I don’t know.”
Ah yes, the Fourth Wall being restored. It also happened in Duffless, when Homer refuses a beer to go home and be with Marge. Moe scoffs, “He’ll be back! And so will you! And you! And you!” (looking directly at the “camera” with that last one). “Of course I’ll be back,” mumbles a drunk Barney. “If you didn’t close, I’d never leave.”
Snake did it. Trying to get Li’l Bandit back off of Homer after he purchased her in a police auction. Homer ducks and misses the wire, Kirk ends up armless. Teehee.
But not in the syndicated version since that scene’s been cut (thereby leaving the viewer to wonder why, at the end, Kirk’s arm is in bandages while he waits in the unemployment line).
Futurama line: Hey, you’re not the guy who delivers the rat droppings!
Saw another (perfect one):
In the recent episode CED’oh, Homer becomes the titular head of the power plant. As his first order of business, he fires Mr. Burns. He then throws him off the balcony where he’s crowd-surfed away. He then says, “Oooh, that looks like fun! Do me!” and immediate jumps over the balcony himself. He falls for a few seconds, and of course we expect him to be too heavy or for the crowd to part right as he lands. Instead, they easily catch and crowd-surf him.
So simple, yet so funny.
How about from “Buffy the Vampire Slayer” - the Dracula episode. Buffy has reduced Drac to a pile of ash on the floor. After Xander spouts gripes a bit about being the guy who ‘gets the funny syphilus’, Buf, Xander & co. wander away.
The pile of ash on the floor swirls and transforms into mist. It coelesces into the revived form of Dracula, alive again to once more…get staked by Buffy a second time.
Buffy: I’ve seen your movies! I know you always come back.
Drac turns to ash, falls to the floor, once again tries to rematerialize but…
Buffy: I’m still here!
The ash stays a pile of ash…and Dracula is never seen again.
Can’t remember the exact context of this one, but Homer is driving, listening to some shock jocks on the radio, and they say something like, “Visit our website at www dot <flush> dot <boing> dot” etc. with a series of lewd sound effects.
Homer chuckles “heh heh heh… website.”
My favorite Simpsons joke.
One from Futurama I remembered:
Bender has a bomb installed in him that will set off if he says the word he says most often, which turns out to be “ass.” We get a David Letterman-style countdown of the top ten words he says. Number 5: “Bite.” Number four: “my.” Number three: “shiny.” Number two…
“Daffodil.”
Krusty watches in dismay as all his possessions, including his private plane, are auctioned off to pay his outstanding taxes:
I love that line! It’s the tone of dawning comprehension that makes you wonder exactly how many time Homer has given up his wallet…
Lenny: “Oh yeah, it’s a great trip; but you can’t see it all in one day!”
Can’t remember the episode, but Homer is falling out of an airplane (or something) and you see him fall toward a pillow factory and… land on the hard concrete roof. He bounces off that and you see a marshmallow truck and… he lands on the hard steel top of the trailer and then tumbles to the street.
It’s been mentioned earlier, but “Guy Incognito” might be my favorite Simpsons joke of all time… maybe tied with Mr. Sparkle.