Deliberate mistake: When Sixsix impacts with the ground due to Greymatter sabotaging his jet pack, the furrow he ploughs into the ground is already present when he skips across the ground.
Deliberate mistake: In one of the later episodes of season 2 Turk is seen being bored in surgery and checking the patient's wristwatch to see how long they have been operating. Patients are not allowed to wear jewelry or watches during surgery as there is a VERY high risk of infection and it might kill them.
Smack in the Middle (2) - S1-E2
Deliberate mistake: Ignoring that its very unlikely all of Jill St. John's copious red hair would fit under a wig that passes for Robin's hair, it's impossible that it would emerge from under that wig looking as full and perfectly styled as it does when she's in the Batcave.
Deliberate mistake: After Ramsey shows Sansa her flayed northern friend, when it cuts to Davos riding the horse through the encampment one of the shots is flipped. Note his sword and his cloak's crossed straps have switched to opposite sides.
Deliberate mistake: When Mary gets to the school where she is going to be teaching, all the children are standing outside wearing shoes. However when they come in to the school they are barefoot. I have a feeling this was done to show how poor the community she was teaching in was supposed to be, but it looked like too cold and rainy of a day to let the actors be outside barefoot.
Deliberate mistake: In the scene with Brian and Beverly going up the stairs, Brian is in the chairlift, and you can see in front of the wig that Peter Kay wears where the red patch is where he has shaved his real hair.
Battlefield - S26-E1
Deliberate mistake: Look for the "creases" in the wall inside the TARDIS, which look as if the wall was just a sheet hung up behind the console. (In fact it actually WAS a sheet and not a "solid" wall - the TARDIS wall prop was apparently unusable due to water damage, due to poor storage between seasons. This also explains the lack of TARDIS interior scenes throughout the rest of season 26: it was not thought worth repairing the TARDIS set [or building a new one] when the show was in imminent danger of being cancelled after season 26).
Deliberate mistake: The newspaper that shows Petrelli's victory has repeated paragraphs through the article. The article seems to be composed of three paragraphs. One paragraph starts with "I was," and two paragraphs start with "The."
Deliberate mistake: When one of the yellow fire trucks moves away from the burning Thompson Tower, the back of the truck is set alight by the flames.
Cold Stones - S6-E11
Deliberate mistake: Tony smashes AJ's front windshield of his Nissan SUV one time with a plastic sports helmet and it leaves a hole 4 times the size. Not only is the scale size of helmet to hole incorrect, but front vehicle windshields don't shatter like that. Modern windshields are made of laminated safety glass, which consists of two curved sheets of glass with a plastic layer laminated between them for safety, and bonded into the window frame. It would've taken many impacts to cause such a hole, not one hit. (00:49:00 - 00:49:45)
Deliberate mistake: In the flashback to Angelus rising from his grave, his and Darla's breath is visible as they exhale. This was going to be removed in post-production, but left in due to budget restrictions.
Deliberate mistake: In Series 1 episode 1 Nick can use a laptop fluently, yet in series 1 episode 2, Nick has to ask where the "." button is.
Deliberate mistake: In the very first episode, the kids are fighting and arguing all throughout the house. Claire then asks Cliff, "Why did we have 4 kids?", referring to Denise, Theo, Rudy, and Vanessa. In all of the following episodes, they actually have 5 kids. I guess they decided to add Sandra (the oldest Huxtable) later down the road.
Mr. Garrity and the Graves - S5-E32
Deliberate mistake: Garrity blackmails the town citizens into paying him not to resurrect their unlamented "loved ones." Amazingly, every man in the saloon just happens to have hundreds of dollars ($500 - $1200 each) in his pocket to pay up with. In 1890 money, that's roughly equivalent to a group of modern-day bar patrons all carrying ten to thirty thousand dollars around in their pockets. The scenario was apparently used in spite of its incredibility just to more quickly advance the plot.
Deliberate mistake: In the scene where Peter Andre and his producer watch the footage of the royal family, in the background you can see princess Diana and the queen mother who had both unfortunately passed away before Little Britain was made. They had to use the old footage but it is still a mistake.
Deliberate mistake: After the party, in the scene where Lucas goes into the cafe, he finds Haley crying. The shot is a distant shot with Lucas and Haley in it. Haley's hands are covering her face. In the next shot, just of Haley, her one hand is over her forehead.
Yankee White - S1-E1
Deliberate mistake: Fornell doesn't recognize Gibbs, but subsequent episodes establish they have a long history together.
Strangers on the Shore - S9-E2
Deliberate mistake: When Del, Rodney and Boycie first arrive in France, there is a side view of the white van they are in and it is clear that the driver is definitely not David Jason.
Episode 306 - S3-E6
Deliberate mistake: In the locker scene where Brian confronts Ben about his steroid use, there are no obvious objects on the lockers (such as slats) that would make the cut and bruise on Brian's back. Brian is not tall enough to have been cut by the top of the locker and Ben didn't pick up in his tirade. (00:25:25)
Deliberate mistake: In the shot where we see the cars in front of Victor's (shortly after Victor gets out of the car and gets back in when the traffic starts moving) you can see that after the white car on the right that there are no more cars even though the episode takes place in a traffic queue! If you listen to the commentary on the DVD, writer David Renwick points out the mistake and informs us that they had a limited number of cars for the shot. (00:11:25)