The Cemetery - S1-E1
Continuity mistake: From the inside view of the window the Hendricks gravestone and the family name is visible on it. From the outside view of the window the gravestone and the Hendricks are facing away from the window.
Continuity mistake: In episode 64, "For Whom The Bell Tolls. And Tolls. And Tolls", Tracy is shown seated at the table with a bowl of cereal - but in the shots immediately before and after, she's not there, nor is there any food at her place. (00:01:10)
Continuity mistake: A UFO crash lands in Canada and sits amidst trees in a wooded area. Just before the craft explodes, the only snow visible is on mountains in the distant background. After it explodes, however, the ground and trees all around it are suddenly covered with snow. (00:36:30)
Continuity mistake: In an episode fairly late in the life of the show, Lou Grant says that when Mary came to interview for a job at the station, she bumped into the desk in his office and said, "Excuse me" to the inanimate object. However, we saw that interview in the very first episode, and no such thing happened.
Kitten Kong - S2-E7
Continuity mistake: Just after Bill puts a duck in the basket of looney animals, all these grey feathers come pouring out. But, the duck hasn't got any grey feathers, and there was nothing in the basket that had any.
This Must Be the Alamo - S4-E5
Continuity mistake: When McCloud and Broadhurst are driving around in the squad car, the vehicle changes in their closeups. Note the light atop the hood, the stickers with the police and unit number on the hood, the rearview mirror's vanishing act, etc.
Continuity mistake: When the gang first arrive at the stately home Albert parks his car next to a coach. When the camera angle changes the car has moved back a few yards, and when the gang leave the car has changed position completely.
Continuity mistake: In the opening credits of the first season of The Odd Couple, Felix is moving in "with his childhood friend", Oscar. In a subsequent season, a storyline does a flashback to say that Felix and Oscar met when they were both jurors at a trial. Soon after, they cut the word "childhood" on most of the openings after people called the station to mention the mistake.
Firefly, Light My Fire - S1-E1
Continuity mistake: Joy exits her house twice: once after the curtains pull back, then a second time after Harmony says his line.