Malcolm in the Middle (2000) - 7 major mistakes

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.]

Continuity: In the episode "Bride of Ida", in the scene where the grandma is talking at the table with Reese and Malcolm, notice the bottle on the table next the the grandma, between takes the cork from the bottle goes from being on top of the bottle to next to the bottle, it changes in almost every different shot.

Revealing: At the start, when Lois tells Hal to raise his arms so she can shave his armpits, if you look at the bottom of the screen you can briefly see that Hal is wearing something to cover up his privates.

Visible crew/equipment: While Malcolm, Reese, Dewey, and Francis are deliberately making their house messy, you can see right above their ceiling a bright light shining down and a black background. It shows that they film their interior of their house on a set.

Continuity: Episode 111 Season 6 "Pearl Harbor" Lois and Jessica enter the house after coming back from going to a musical. As Lois comes through the door her purse slips off her shoulder and she catches it around her elbow. In the next shot a second later, the purse is back up on her shoulder.

Revealing: In season 5, second episode, in an imagination sequence Reese and Malcolm are throwing around Jamie, but you can see it is a doll.

Continuity: Season 6, episode 7: "Hal Sleepwalks"; At school, Dewey stops the shouting match between the two opponents. In the shots facing Dewey, the boy's arms are held way up high in front of him, but in the shots facing the kids, the boy's arms are down at his sides.