My Sister, the Homemaker - S5-E12
Visible crew/equipment: At the beginning of the episode, Jeannie is talking on the phone by the stairs and her sister is hiding behind the banister. Her sister stands up for a moment and shows her full face, revealing that it is actually Barbara Eden's stand-in wearing the green costume.
The Night Dr. Loveless Died - S3-E4
Visible crew/equipment: The arm of the actual carriage driver is visible poking through the back of the carriage, slapping the horse and signaling it when to stop/proceed with a second set of reins, showing the actor in the carriage was not controlling the horse at all.
Two Nazis for the Price of One - S3-E17
Visible crew/equipment: A string is seen attached to Colonel Klink's cap that is used to yank off the cap after Colonel Mannheim fires his pistol at Klink.
No Exchange on Damaged Merchandise - S1-E9
Visible crew/equipment: During the opening sequence, the bad guys' red Ford Galaxy reflects a bank of studio lights when the door is opened. (00:03:30)
Visible crew/equipment: You can see a modern high voltage power tower on the mountain in the background while they are lining up for inspection. (00:08:00)
Visible crew/equipment: When Will and Dr. Smith first come upon the Trader's encampment, just as the dogs start to attack you can see the head of a crew member (dog trainer?) bob in and out of view from directly behind where the dog on the right was lying...from behind the boxes stacked on the ship's platform. (00:08:38)
Visible crew/equipment: When Max and 99 have reached the mansion, they both get out of the car to look in the trunk. As they start walking, some lightning occurs. If you look up at the top, you can see where the fake sky ends and the visible back of the stage begins.