Shoes, Hats, Pickle Jar Lids - S5-E9
Revealing mistake: When Charlie is in the Ferrari, his gets a call from Teddy. When Charlie brings the iPhone to his ear and talks to Teddy, you can see that the iPhone is upside down showing that no one actually called his phone.
Clash!! Sonic VS Knuckles - S1-E5
Revealing mistake: Right at the end of the episode, when Amy is telling Knuckles he should apologize, Amy has two right hands.
Revealing mistake: In the scene in the kitchen, Lucille Bluth takes a bottle of "Bushmills" (a brand or Irish whiskey) out of a grocery bag during a scene in the episode; however the liquid inside is clear/transparent and obviously not whiskey.
Revealing mistake: During the dinner scene where Dave is thinking about Arsenio Hall eating cheese, Arsenio starts complaining about how good the cheese is. After punching one guy, he goes up to another and slaps him in the face. When he slaps him you can see he misses the guy's face by a good inch or so.
Revealing mistake: The phone message that Ryan leaves on Luke's voicemail is different to what he originally said, which is "I want to make sure you took care of it. Take care of it," but the message recorded is, "I'm just calling to make sure you took care of it. Take care of it." Also the background sounds from the club - the music, people talking, etc, are missing.
Revealing mistake: When Bubbles rips her wig off, her face is obviously paler than the top of her head, due to the fat-suit Matt Lucas was wearing.
Revealing mistake: In the episode with Fast Eddie McClintock, there are two revealing mistakes in the scene where Fast Eddie jumps the roadblock. First, the ramp he jumps off of is visible in numerous shots before he shows up. Second, explosive charges can be seen in the wheel wells of the police cars before they run over the spike strips.
Revealing mistake: Reapers look 'different' in reflections and recordings, yet sometimes you can catch them with 'normal' reflections, eg. Rube in the diner window.