Police Squad! (1982)

Six episodes, and barely a frame without a gag in it. This 1982 parody of cop shows has Leslie Nielsen playing Frank Drebin perfectly straight while puns, literal-minded misunderstandings and sight gags pile up behind him, often in the background where you have to spot them yourself. ABC dropped it after a single season, reportedly because the viewer had to watch it to appreciate it, which is exactly the point here. It led to The Naked Gun films, and the whole series is short enough to finish in one evening.