Homer pours an entire bottle of lighter fluid onto his barbecue. Then another bottle. Then he goes to light it... and it lights as normal, and he proceeds to cook. Of course, in a different episode with a similar scene, the lit barbecue ignites into a mushroom cloud that can be seen from across the city.
In another episode, Homer invites most of Springfield's men to get front seats for the Superbowl. But the cards turn out to be faked, and they have to look for another way in. Then they see a waiting wardrobe-on-wheels bearing dozens of marching band uniforms waiting at the rear entrance. They use... the wardrobe-on-wheels to topple two policemen standing next to entrance, and rush past them into the arena's interior. It gets them arrested almost immediately.
In The Movie, Homer is nailing shingles, his thumb clearly over the head of the nail. He gets the claw end of the hammer on his eye instead. The gag is revisited at the end, where Homer has clearly learned his lesson, keeping his thumb out of the way and wearing safety goggles. He hammers the nail perfectly... into his thigh.
Also from the movie, Bart skateboards across town completely naked, with various objects like fences and blown bubbles censoring his privates along the way. Just when it seems like the scene is going to end, he goes past a hedge that hides everything but!
Again from the movie when Homer is trying to work out how to reach the hole at the top of the dome to get inside it. He stumbles across a military inventory containing a highly visible jetpack, and gasps in delight, before picking up a much less obvious tube of superglue and trying to use it to crawl up the side Spiderman-style. The plan doesn't work too well...
"The PTA Disbands" has the Springfield Elementary students, on their way to Fort Springfield, trying to slow the dilapidated old bus by holding their coats out the window. Cut to a Fort Springfield tour guide showing people a cannon, explaining it's "fully restored and is in ready-to-fire condition" but won't be fired since it's aimed directly at a manned lookout tower, and adding that these old cannons can easily go off if they get a slight shock. The bus crashes straight into it ... and nothing happens. "Of course, for safety reasons, we don't keep the cannon loaded. That's just common sense."
In "And Maggie Makes Three", Patty and Selma learn that Marge is pregnant; she makes them promise not to tell Homer. They go home, and Patty gets out a phone book, opens it to the first page, and calls someone named A. Aaronson, telling him that Marge is pregnant. After that, the scene cuts to Patty, on the last page of the phone book, telling the same to a man named Zykowski. Then she heaves a sigh of relief... and says: "Aaronson and Zykowski are the two biggest gossips in town. In an hour, everyone will know."
Another episode has Homer lose track of Lisa. He decides that he needs to get up high to be able to scan the surrounding city for her and then goes to a vendor selling balloons, seemingly leading up to a joke that Homer is dumb enough to think he could float using a handful of balloons.... Then, he offers the balloons to a cherry pick driver in exchange for using his machine to lift him up. It works.
"Well, I've already got some balloons... but they're not this nice. Deal!"
In "Marge on the Lam", Marge and Ruth Powers drive up to a bar with a large neon sign saying "SH T KICKERS" (the letter between H and T is burned out). Marge comments that she's heard a lot about "Shot Kickers".
In the same episode, only a moment later, we see the two women inside, and Marge is approached by a burly man who asks if she feels like "gettin' lucky." Marge replies that she is lucky, having a husband and three wonderful children, and thanks him for the compliment. He adopts a more threatening tone, saying he ALWAYS gets what he wants. Marge clarifies that she said "No." He is suddenly apologetic, says he misunderstood her, and backs off politely.
A similar gag is used in a later episode where Marge and Homer attempt to place a banner on a female judge's house, and the first two letters can be seen as "BI-", implying that it's "Bitch." They reveal the full banner and it turns out to read "Big Meanie."
In "Realty Bites" Homer bought Snake's confiscated car, and one of Snake's plans to kill Homer involved laying out some piano wire to decapitate him as he drives by. Homer ducks to pick up a gumball right as the wire goes over him and is then followed by Kirk Van Houten in his car indignantly holding up a sandwich:
Kirk: I told that idiot to slice my sandwich! (wire cuts half of his arm off) Kirk:Ow.
From "Marge vs. Singles, Seniors, Childless Couples, Teens And Gays"
Lindsey Neagle: Let's destroy every child... friendly thing in town!
Another episode has Homer and Larry, the son of Mr. Burns, on the run from the law after Homer pretends to kidnap Larry to make his father love him (It Makes Sense in Context). At one point, the two run inside a costume shop and a few seconds later, two figures in costumes that match their sizes walk out, implying that the two are now in disguise. Then shortly after that we cut into the costume shot where the two are actually hiding out in the back closet, and are promptly kicked out by the store's owner.
In "War of the Simpsons," Bart complains about being sent to bed before the Simpson's party begins, saying, "You can't have any fun in bed." Homer chuckles and says, "Oh, son, when you're older you'll know better." We then see an Imagine Spot where Homer is in bed eating a giant sandwich.
Almost the exact same joke is done in "The Otto Show," only this time with a pizza in the back of a car.
In "Lisa the Beauty Queen" Homer tells Bart to always compliment women on how they look and he'll "get something in return." When Bart asks what, Homer says he'll tell Bart when he's older. Homer then imagines lying in a hammock while Marge mows the lawn.
In "Skinner's Sense of Snow" the Simpsons go to an Expy of Cirque du Soleil. While watching some contortionists, Marge whispers to Homer that their poses are giving her ideas. She then imagines herself in those poses... cleaning the bathroom.
Combined with Exact Words in "Kamp Krusty." Homer is on a picnic with Marge during twilight and he's rubbing her shoulders and both have a seductive look. Marge says she's worried they'll miss the fireworks. Homer replies, "We have all the fireworks we need right here." He then pulls back a blanket to reveal a picnic basket filled with fireworks.
A similar joke happens in "Special Edna". Homer and Marge watch some fireworks, leading Homer to say that they should make some fireworks of their own. Marge seductively agrees...then Homer brings in a cone filled with gunpowder and Marge starts patting it down.
Homer is looking for a new drinking hole and wanders into the 'She She Lounge' full of butch women:
Homer: Wait a minute... there's something bothering me about this place... I know! This lesbian bar doesn't have a fire exit! Enjoy your death trap, ladies!
Then there's the Treehouse of Horror episode where Homer changes history causing Springfield to became a totalitarian state run by Ned Flanders. When Homer attempts to escape back to his house and activate the toaster/time machine again to undo the damage, Flanders releases some guard dogs to stop him. Homer then pulls out a string of hot dog wieners, saying "these will help me escape!," which leads you to think he's going to throw the wieners to the guard dogs and they'll be too distracted with eating them to chase him anymore. Instead, Homer eats them himself, which amazingly enough gives him an extra burst of energy that lets him make it back to his house.
The same season, a similar gag is used in "Lemon of Troy" when Bart is being chased by a guard dog. Homer attempts to distract it by throwing a steak its way, but instead the dog swallows it whole while still chasing after Bart, leading Homer to exclaim, "Run boy! He has a taste for meat now!"
Also in that same episode, Bart is discouraged because he can't find the lemon tree. He says that the raid was as useless as the "yellow lemon-shaped rock" he notices behind him, leading the viewer to believe that Bart's about to realize the "rock" is actually a lemon from the tree.
Bart: Wait a minute...there's a lemon behind that rock!
Homer imagines himself at the Super Bowl in "Sunday, cruddy sunday":
Coach: Dang! That was my last quarterback. Now what am I gonna do? (The coach looks into the crowd, and sees Homer) You! Homer: Me? Coach: Yeah, you! Get your hand off my wife's leg!
In "Homer the Clown", just after Krusty barges into Fat Tony's club:
Legs: (gasps) I'm seeing double here: four Krustys!
In "Kiss, Kiss, Bangalore", before showing his employees an Outsourcing-themed movie, Mr. Burns asked for a minute of silence for the employees who died doing something heroic. Whatever it was, we never got to learn because Homer interrupted him by demanding the movie and the topic was never brought up again.
Superintendent Chalmers and Principal Skinner doing a sketch for a talent show:
Chalmers: Well, Seymour, it seems we've put together a baseball team, and I was wondering; who's on first? Skinner: Yes, not the pronoun, but rather a player with the unlikely name of 'Who', is on first! Chalmers: Well, that's just great, Seymour. We've been out here six seconds and you've already managed to blow the routine!
In "Homer Loves Flanders", Homer is sad that he doesn't have tickets for the big Springfield vs Shelbyville game and Lisa attempts to put it in perspective:
Lisa: It's just another chapter in the pointless rivalry between Springfield and Shelbyville. They built a mini-mall, so we built a bigger mini-mall. They made the world's largest pizza, so we burnt down their city hall.
In "Thirty Minutes Over Tokyo", we think Homer is being racist at first.
Homer: If we wanted to see some Japanese people, we could have gone to the zoo.
Homer: What? The guy who washes the elephants is Japanese. His name's Takashi. He's in my book club.
In "Bart's Girlfriend", we think Bart is marking off the days on his calendar avoiding seeing Jessica Lovejoy only to conclude, "There. I just need to make it this many days," and re-mark the first day.
In "Viva Ned Flanders", in order to escape the women they accidentally married while drunk, Homer and Ned momentarily mug two janitors in order to steal their uniforms. After some brief sounds of violence occur, the two janitors exit unscathed while Homer and Ned appear brutally beaten up.
"Barting Over" contains a series of videos entitled "Homer and Marge Get Dirty"...only to revealed to be the two of them carving pumpkins.