Continuity mistake: When Mummy is asking Peppa about her new red shoes Mr Dinosaur is not in George's bed, but when George says goodnight, Mr Dinosaur is right next to him.
Encounter at Farpoint (1) - S1-E1
Revealing mistake: When Q freezes Torres on the bridge, it is easy to tell that directional hoses were used for the effect. (00:06:25)
She Loves Me, She Loves Me Not - S8-E2
Visible crew/equipment: After Jack talks to Larry about the magazine quiz Jack asks Janet if anything's been bothering her, and just as Terri walks out of the kitchen holding the two cans, a crew member's hand can be seen behind Terri placing a bag on the counter. (00:04:15)
Visible crew/equipment: When Dewey yells for Lois because the bow was put on the present, if you look to the left of Lois, you will see a crewmember kneeling down, handing Lois the Red Dress, who is holding a bucket of water. He quickly gets out of the camera's view. [This is on the DVD of the first season. Someone said on the audio commentary that after catching it, they deliberately left it in to see if anyone would spot it. It's still a mistake, but that's why it's there.]
Other mistake: Cook and Effy manage to fall through Pandora's Mum's wardrobe, into the next door neighbor's bedroom. But this is not possible as the neighbors' houses are detached.
Episode #1.3 - S1-E3
Continuity mistake: Vera fires the gun several times, and later tells Justice Wargrave that the gun is empty, meaning that all the cartridges in it would be spent. When the judge loads his one bullet into the chamber, he does so in a gun where all five cartridge svisible are unspent.
Kobol's Last Gleaming (2) - S1-E15
Visible crew/equipment: In the scene where Starbuck attempts to retrieve Apollo's arrow, a crewman in a red tee shirt and dark vest can be seen standing just behind and to the right of the display case as she is shooting out the glass.
Free for All - S1-E4
Continuity mistake: Throughout the episode, Number 6's lapels switch from having solid to broken white piping and back again.
Visible crew/equipment: When Nina's just been shot, and makes it to the barn to call CTU (around 7.10am), while she's speaking on the phone there's a cameraman visible on the right hand side (DVD). (00:12:40)
Deliberate mistake: When the Doctor begins to "fade" in the transporter room his mobile emitter fades with him. Since it's made of solid matter and is not a hologram, this shouldn't be possible.
Plot hole: Hippolyta tells Hawkgirl of Aresia's background of being born in the outside world, the war in her country and right up to her drifting to the shores of Themyscira. It would be impossible for her to know anything of Aresia's background as in part two, it's explained that the captain of the ship who saved Aresia died shortly after reaching Themyscira and therefore would not have been able to tell Hippolyta anything.
Girl Trouble / School Dance - S3-E18
Continuity mistake: Besides the fact that when Helga is sharpening her pencil, the desk arrangement changes, one of the students visible when she looks at Arnold is... Helga. This happens because the shot is taken from the episode "Helga's Love Potion."
The People vs. the Fonz - S11-E11
Factual error: When the Cunninghams are talking about Fonz's trial, Mr. Cunningham can be seen wearing a digital watch. Digital watches didn't exist in the 50's.
Other mistake: When the show aired in 1990, in the pilot episode Brenda falls for Jason. She later on reveals herself to be a "16 year old junior" in high school. Season 2 opens up with the gang on summer break which technically would make them going into their senior year. It wasn't until Season 3 that they were going into their senior year. They graduated in 1993 from West Beverly but the show debuted in 1990 so technically they should have been sophomores.
Rockets, Communists, and the Dewey Decimal System - S1-E2
Other mistake: As Young Sheldon is a prequel series to Big Bang Theory, this episode is at odds with episode 2-13 of Big Bang Theory, "The Friendship Algorithm," in which Sheldon is unfamiliar with books like "How to Make Friends and Influence People," which he reads in this episode of Young Sheldon, produced nine years later but taking place twenty years earlier.
Character mistake: When Beth and her mother discuss the agent's fee of 15%, Beth says it is $49.54. However the prize money was $500, the expenses were $172.30, which leaves them $327.70. 15% of $327.70 equals $49.16. (00:10:00)
Factual error: In the mall where Jimmy meets Irene there is the Pandora logo in the background when Jimmy is going up the escalator. Pandora didn't open its first store in New Mexico until 2013. (00:27:00 - 00:28:00)
Confinement - S2-E5
Continuity mistake: Ruby asks Ash where the the Kandarian Dagger is. He says that it was confiscated by the police. In the previous episode, she had and used it, and they have not interacted in the intervening time period.
Todos Los Hombres del Presidente - S3-E9
Visible crew/equipment: During the car crash, one of the camera shots is from above and you can see a camera vehicle moving into the shot from the bottom with the camera mounted in front of the vehicle. (00:35:25)