The Simpsons (1989)

Bart's Comet - S6-E14

Continuity mistake: When Bart is first introduced to the Superfriends, Ham moves around the table a bit. First he is seen sitting next to the kid with dark, curly hair, and you can see a plate in between him and Bart's plate, indicating that someone else is sitting there. This someone turns out to be Lisa, who after she is introduced, switches seats with Ham, making Ham sit next to Bart.

Dude, Where's My Ranch? - S14-E18

Continuity mistake: When Homer is playing the song on the piano, one of the photo frames on the top of it keeps changing from square to oval.

Hamster

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.

Homer vs. Patty and Selma - S6-E17

Continuity mistake: When Homer is walking upstairs after kicking Patty and Selma out for the second time, the wall that Homer was approaching is a darker colour than it usually is, and Homer walked up the stairs slowly. But a second later he closed a door, indicating that he went into a room. Are we really to believe that he could go very quickly from the stairs to a room in a matter of seconds?

Marge vs. the Monorail - S4-E12

Continuity mistake: Just after the Monorail has been seized by the "anchor" getting caught on the donut sign, the long stripe at the top of the side of the Monorail changes from being red to purple.

Bart After Dark - S8-E5

Continuity mistake: During the big song near the end, there is a birds eye view of everybody outside dancing and singing, and Krusty, Chief Wiggum and Skinner are there outside with everyone. But in the very next shot, they all appear out one of the windows, singing a line to the song.

Hamster

Diatribe of a Mad Housewife - S15-E10

Continuity mistake: When Marge is typing her novel on the computer, in one close-up shot of her we see there is a pencil on one side of the table and a pot of flowers on the other. Yet when the shot changes to further away we can see that the pencil has been replaced by a napki, a pot with two pencils has appeared, and the flowers have moved to this side of the table as well. (00:06:20)

Much Apu About Nothing - S7-E23

Continuity mistake: When Homer swings on the electric cable when attempting to get to his car, the cable has just appeared from nowhere because, the previous 'birds eye view' shot showed no cable.

Much Apu About Nothing - S7-E23

Continuity mistake: When Ned is struggling to get in the house at the beginning the door knob is light brown, then dark brown in another shot.

Simpsons Spin-off Showcase - S8-E24

Continuity mistake: In the beaver sketch, "Lisa" is holding Maggie in front of her to show everyone her first tooth. In the next shot, Maggie is instantly to her side.

Lisa the Simpson - S9-E17

Continuity mistake: After Apu & Homer find Jasper in the freezer. Apu removes a note from his hand. Minutes later Dr. Nick walks in the door you see Jasper still holding the note then disappears again when Dr. Nick opens the freezer door.

Milhouse Doesn't Live Here Anymore - S15-E12

Continuity mistake: When Bart and Milhouse arrive at Milhouse's home, there is a red car in the driveway. When Bart screams, it has gone. (00:05:10)

Marge vs. Singles, Seniors, Childless Couples and Teens, and Gays - S15-E8

Continuity mistake: When Homer sneaks into Maggie's room to smash the CD player, there is a yellow box with musical notes painted on it. The notes are different in each shot. (00:02:30)

I Married Marge - S3-E12

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)

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)

Lisa's Pony - S3-E8

Continuity mistake: During Lisa's performance, In one shot of the audience we see, from left to right: Ned Flanders, Maude Flanders and some lady. The rest of the talent show showed us that Jasper was sitting where the lady was. (00:05:45)

Lisa the Iconoclast - S7-E16

Continuity mistake: When Lisa first discovers Jebadiah's confession, she is holding the fyffe and wearing his racoon hat, the screen fades to black (I'm guessing for the ad break) but when it comes back Lisa is standing in exactly the same position, still reading the confession, still holding the fyffe, but no longer wearing the hat.

Bye Bye Nerdy - S12-E16

Continuity mistake: There are two problems with Lisa's Indian burns. When we first see them, she has 4 burns. Then, while she is showing them to the bullies, there are 3, then 4 again. Then, in the very next scene when she is walking with Nelson in the schoolyard, they are gone altogether.

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.

The Simpsons Halloween Special: Tree House of Horror - S2-E3

Continuity mistake: When the Simpsons are about to eat on the spaceship, in one shot just before they eat there are 3 candles on the table, and when they all sit down they're gone. (00:10:40)