Continuity mistake: When Homer goes to work, and Mr. Burns starts complaining about him, we can see that the two pictures are on the far side of the yellow machine on his desk. But then when the shot changes, they are on the other side of the yellow machine. (00:13:45)
Continuity mistake: When the family is talking at the dinner table about going to see Truckasaurus, the amount of food on everyone's plate continually changes between shots. (00:03:40 - 00:04:25)
Continuity mistake: When at the dinner table, Marge tells Homer and Bart that they can go to see Truck-o-saurus. In one shot Bart has his hands on the dinner table, but in the next shot his arms are by his side. (00:04:20)
My Big Fat Geek Wedding - S15-E17
Continuity mistake: The first shot in the transition from the bachelorette party to the bachelor party shows Skinner drinking beer. He finishes the bottle, and in the next shot it's full again.
Continuity mistake: On Lisa's plate at dinner she has no mashed potato. During the lamb vision, her pork chops are now smaller and there's now mashed potato on her plate.
Continuity mistake: When Homer sulks on the couch, he has a pillow under his head, which is pink. In a closer shot, the pillow turns light blue, but in another shot, the cushion has turned pink again. (00:17:10)
Radio Bart - S3-E13
Revealing mistake: At Wall E. Weasel's, when Nelson is throwing balls into the 'Skeeball' machine, the animation is repeated because Bart keeps moving in and out of the camera's view. (00:04:10)
Like Father, Like Klown - S3-E6
Continuity mistake: In Lovejoy's office, the clock on the wall keeps changing. (00:13:05)
Continuity mistake: At the beginning, when the bus is driving to the school, the streetlights outside disappear/reappear between shots. (00:01:30 - 00:02:20)
Continuity mistake: When Bart and Ralph are in the prison and see the key, the window's shadow is of four squared panels. When they go to pick the key up and the rat takes it the shadow shows 3 rectangular panels.
Continuity mistake: When the Simpson family and Jay Sherman are having dinner, things like the food from their plates, their knives and forks and even Homer's burping trophy disappear and then reappear for a couple of seconds before disappearing again.
Continuity mistake: When Mr. Burns and Smithers go to leave, the beak-like knocker has disappeared from the Simpsons' front door.
The Simpsons Halloween Special: Tree House of Horror - S2-E3
Continuity mistake: In "Hungry Are The Damned", when the family are looking up at the UFO and Homer says that the burgers are getting cold, the burger he is eating has a bite out of it. In his close-up it is a whole burger.
Revealing mistake: At the car convention, Homer chides Bart through the windscreen of Bonnie and Clyde's car. However, Homer's body is not seen through the holes in the windshield, which shows that the holes in the windshield were achieved via a layer of red-coloured holes. (00:04:25)
Tree House of Horror X - S11-E4
Other mistake: In "Desperately Xeeking Xena", at one point she approaches the Collector, who is about to get a light saber. We can see the back of the pouch that Xena is in, but the tape on the other side isn't visible, even though it is a transparent pouch.
Tree House of Horror V - S6-E6
Continuity mistake: In 'Time and Punishment,' Homer goes back in time, then returns, and the kitchen table has plates of food, cutlery and glasses all set out. Then when Homer is informed that Ned is the Lord of the Universe, the house starts shaking, but you can see the table is now totally clear. (00:11:15)
Continuity mistake: When the Simpsons are driving to Cypress Creek the arrangement of luggage on the roof of the car changes depending on their stage in the journey.
Tree House of Horror XII - S13-E1
Continuity mistake: When the family finds Homer, he has an hole behind his head and you can see his brain, but it's not there later.
The Simpsons Christmas Special: Simpsons Roasting on an Open Fire - S1-E1
Continuity mistake: When Homer walks up The Front drive you can see the road and there are no markings on it. But when he turns to look at his house, there are orange lines running down the road. (00:08:50)
Continuity mistake: When Homer is on stage in Springfield and preparing to get hit by the cannonball, the speaker-tower, behind and slightly to the left of him, completely disappears in the wide shot right before Homer jumps off stage.