Revealing mistake: During the fight scene at the end when Buffy is fighting the demons you see her throw one of the demons off the platform. If you watch him fall you can see him land safely on a conveniently placed mat. (00:38:10)
Revelations - S5-E22
Revealing mistake: Just before Teal'c and O'Neill get to the engine room door, Carter can be seen hiding around the corner. (00:27:40)
Revealing mistake: When Georgia walks into Billy's office naked, a triangle-lamp will cover her "naked" breasts. Look closely, for at one point you can see the white, strapless bra.
Revealing mistake: When Alan serenades Jill, near the end of the song, the guitar player removes his hand from his guitar briefly but the guitar part continues to play (it's being synthesised as part of the keyboard's rhythm track). (00:19:10)
Pilot: The Spirit of Christmas (Jesus vs. Santa) - S1-E1
Revealing mistake: Each time Jesus turns his head to speak to the children when he is beating Santa Claus, he has two left arms.
Revealing mistake: The footage of Monkey Bulk doing flips is just one backflip forwarded and reversed several times - as evident by the movements of the people behind them.
Revealing mistake: Whilst Bobby is reversing the truck before hitting the flagpole in Bill's yard we see the driveway in front of the truck. The very next shot shows Peggy from behind the truck instructing him how far to go to the flag pole and you can see they have used the same background as the shot before from the other angle. You can tell this as both shots are the same background as both angles despite from different viewpoints are exactly the same items and objects in both shots. Added to this there is a driveway in each shot, and Bill doesn't have 2 driveways in his backyard.
Revealing mistake: Dead lady blinks when Barnaby enters the room.
Revealing mistake: Right after TJ and friends are looking at the "thermometers" of cans, the Ashleys have at least 4 crates of cans that they bring in on forklifts. However, the end result is 4,362 cans for the Ashleys. This may seem kind of picky, but I think there was more cans than 4,362.
Suggested correction: This is literally just an assumption, and nothing else. 4,362 is a pretty huge number, and with the amount of cans that we see the Ashleys collect in the episode, combined with the amount of cans that they and the rest of Miss Furley's class collected off-screen, it is perfectly believable that Miss Furley's class would end up collecting that amount of cans.
Super Nova - S1-E2
Revealing mistake: When Stan, Xev and Kai are walking to the Memory Chamber, they seem to walk out of a two dimensional line at the lower left into the scene. The set and green screen weren't quite synched.
Revealing mistake: When Maya picks up Finch and slams him against the wall, you can see David Spade look down and step up onto an offscreen platform to give the illusion that Maya is holding him up. (00:13:35)
Revealing mistake: A little oversight on the part of the producers. At the final scores that we are shown, Amy has $10,000, TJ has $9,800, and Travis has $2,400. This all adds up to $22,200. Even if they only answered $400 questions (which we can see that they don't), that's about 55 questions at best, only in the first half. That would run way longer, probably about three or four times as long, as any normal game show. And there's no mention of any other rules regarding the scores so there's no reason to think that there are bonus questions that could raise it that much.
Revealing mistake: In every episode, the windows in both the kitchen and living room areas never reveal any scenery outside them during the day or any reflections from the inside at night.
Revealing mistake: As the RCV enters the gravel field with the bomb, you can see a person in shorts walking casually in the background, despite the area being sealed off.
Revealing mistake: Creek reads a newspaper article about Tracy, a missing schoolgirl. The first paragraph of the article is about the schoolgirl, but the rest is about John Major (who had just been ousted by Tony Blair as prime minister when the episode was first aired, but, assuming this was filmed some months earlier, would still have been in power). The first line of the article following the first paragraph starts mid-sentence, as if the first paragraph has simply been pasted over the top of the existing article. This mistake is surprising as there is a photograph of John Major alongside the article and the newspaper remains in shot long enough for it to be spotted without the need to pause the DVD or video.
Demon Suite Murder Case: File 2 - S1-E17
Revealing mistake: When Kindaichi looks the name up in the French dictionary, the pages are entirely made up of the same paragraph repeated over and over. (00:08:50)