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.
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: When Siegfried throws the cup into the air and Doctor T holds it up with his force field, a wire is visible holding the cup in the air.
Carpetbagging, Anyone? - S2-E28
Visible crew/equipment: In the opening sequence, when troopers Stanley and Livingstone are heading towards the Captain's office, shadows of a production light and a boom mike and operator are seen on the ground.
Katokutai shutsugeki seyo - S1-E4
Visible crew/equipment: When Neronga is shown destroying the power station, one specific shot shows Neronga roaring while tilting its head upwards. In the next shot, two metal wires can be seen being connected on top of the head, possibly used for the previous Neronga's roaring shot. (00:19:24)
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)