Continuity mistake: When Homer says, "You can't take our donuts," his hat is red. But in the next shot and in every other shot of Homer, his hat is blue. This is pointed out on the audio commentary on the Season 4 DVD. (00:12:35)
'Tis the Fifteenth Season - S15-E7
Continuity mistake: After Homer decides that he doesn't want to sleep with Marge, he goes downstairs and watches TV. He moves to a different side of the sofa between shots.
'Tis the Fifteenth Season - S15-E7
Continuity mistake: After the family discover the astrolobe, the gift tag disappears from its wrapping. (00:07:25)
Continuity mistake: Marge tells Bart not feed Maggie the Monopoly houses. Bart shows the box and says that there's enough of them. The shot later, the box has disappeared. (00:16:15)
Kamp Krusty - S4-E1
Continuity mistake: In the shot where Kearney is reading the letter sent by Marge whilst he is eating the jellybean cookies, there is a quick shot of Kearney's hand going to his mouth with the cookie to eat it. Note that there is nothing on his wrist. In the next shot where it is revealed that Kearney is reading the letter rather than Bart or Lisa, he has spiky, black collars on his wrist. (00:14:25)
Continuity mistake: When Cletus takes a picture of one of the robots at the parade, the old lady next to him changes from black to white between shots.
Continuity mistake: When Homer tells Carl and Lenny about the movie they watched, they change positions, and there is much more on the table. (00:03:35)
Revealing mistake: If you look carefully in Mr. Burns' surveillance cameras, the workers are identical. (00:02:50)
Continuity mistake: Bart's drawing of Principal Skinner is gone when Mrs. Krabappel says that he is missing. (00:14:05)
Tree House of Horror V - S6-E6
Continuity mistake: When Skinner is cooking the kids, he and the cook are chasing Bart, Lisa, and Milhouse. From the back, he has an apron tied around his neck. In the next shot, he puts on an apron.
Tree House of Horror V - S6-E6
Continuity mistake: In 'Time and Punishment,' in the basement, as soon as Homer puts the back of the toaster back on, two pink wires taped to the side of the toaster suddenly appear. (00:09:30)
Kamp Krusty - S4-E1
Continuity mistake: When the kids rip Krusty's shirt to see if it is the real him he buttons his shirt up then in the next shot his shirt is still torn.
Continuity mistake: When Marge's sisters start smoking in the flashback, there is only one ledge on the wall behind them. In the next shot there are three ledges and a clock. (00:04:05)
Bart's Friend Falls in Love - S3-E23
Revealing mistake: When Bart tells Otto not to leave due to Milhouse not being on the bus, when Otto replies you can see that his left arm up to the headphone cable flashes pink for a frame. (00:07:45)
Burns Verkaufen der Kraftwerk - S3-E11
Continuity mistake: Homer drives his normal car to the plant's parking lot. When he and Carl meet, his car has changed to being blue. (00:07:00)
Bart's Friend Falls in Love - S3-E23
Continuity mistake: When Samantha is introduced to Bart's class, to Wendell's right and a boy sitting in front of him there is an empty column of desks. But in the overhead shot, this column has disappeared. (00:04:45)
Itchy and Scratchy: The Movie - S4-E6
Continuity mistake: When there is a queue to see the movie, it stretches right back to the Simpson house, and we see Bart looking through the window. However, when Homer talks to Bart whilst sitting on the window, the queue has disappeared. (00:16:45)
Continuity mistake: When we see Skinner's car before the newspapers fall on him, it is a light-brownish color. When the police arrive, it is the same color as the cop cars. (00:19:10)
Tree House of Horror II: A Simpsons Halloween - S3-E7
Continuity mistake: During the 'Next week, on the Simpsons' clip, Maggie changes where she sits at the table. Lisa also changes where she sits, as you can see in the background. (00:21:45)
Continuity mistake: As Homer and Marge are singing in the car, there is one exterior shot of the car, showing it is yellow, but the rest of the scene it is green. (00:05:55)