Mistakes in the IMDb top 250
Other mistake: When young Vito Corleone shoots Fanucci in the chest at the doorway to his apartment, in a continuous shot, a wound/blood bursts from Fanucci's white vest. When Fanucci proceeds to tear his vest open seemingly in disbelief he has been shot, there is no entry-wound, blood or hole in his white shirt directly under where the wound appeared in his vest.
5: 12 Angry Men
7: Pulp Fiction
Continuity mistake: In the second half of the film, Frodo has a scar on his lower right cheek, close to his chin. Many times throughout the rest of the film the scar changes position and size on his right cheek. It also appears on his left cheek in flipped shots (most obviously on the slopes of Mount Doom when Sam is cradling his head).
10: Fight Club
Continuity mistake: Close to the end when Edward Norton runs up to the front of the empty building and Brad Pitt appears, he tries to break the glass door by pushing a bench into the door, but it doesn't work. He doesn't move the bench and he then shoots at the glass and breaks it. When it shows him walking through the broken door, the bench has disappeared.
Continuity mistake: As Boromir and Aragorn talk right before Boromir dies, you can see Boromir's right hand gripping Aragorn's left shoulder in the shot from behind Aragorn's right shoulder, but when the camera view changes to Boromir's perspective, looking up at Aragorn, his hand is not there. The scene goes back and forth between these two views several times.
12: Forrest Gump
Continuity mistake: When one of the Storm Troopers unties Solo before he is put into the carbonite, watch his wardrobe - he has a disappearing / reappearing jacket on. This is fixed to an extent on the DVD - the jacket is now lightened to almost match his shirt, but it's still shiny like leather.
Continuity mistake: At Henneth Annun, Sam suggests to Frodo to use the Ring to escape. Frodo and Sam are sitting in front of three barrels and also in the room are sacks, a crate and candles burning behind them. When Faramir arrives, Frodo and Sam are now sitting on blankets, there are no barrels in sight, the walls are different, there is an extra crate, with food on one and the candles are grouped differently.
18: The Matrix
19: Seven Samurai
Factual error: Toshiro Mifune's character, Kikuchiyo, travels to the bandits' camp and steals one of their two remaining fuselock muskets. Shortly afterward, the bandits fire twice at the samurai within five seconds with their last firearm. A fuselock takes as much as two minutes to reload, prime, and fire.