Deliveries in the Rear, I think, has a great storyline and a truly chilling end. A surgery instructor guy has these two weird guys deliver bodys to him through the back of the building when he teaches. But at the end of the episode the two weird guys bring him the body of his girlfriend, who they have apparently murdered.
I believe this is truly one of the spookiest and most well written episodes of the masterpiece that his Night Gallery. Great story with a great ending that I do not think anyone really could have predicted. Truly a great episode.