I recently discovered ME-TV which airs episodes of great (in retrospect many are awful) old shows like Family Affair, Petticoat Junction, Gomer Pyle, Love American Style (an old favorite of mine), Cannon, Mission Impossible, Hawaii Five-O, Kojack, Rockford Files, Batman, That Girl, My Three Sons and a bunch of other shows that were staples of my growing up years.
One show that I watched religiously with my grandmother was Perry Mason. Still love the theme song.
So a Mason episode was on the other night and as I watched it I discovered that even the great litigator Mason could jump the shark. This may not be the only episode in which Mason leaped astride the beast of the deep, but he was certainly clinging to a dorsal fin in Episode 239 of his 271 episode run: The Case of the Grinning Gorilla.
Della buys a package of junk at an auction and it turns out that some rich guy wants it back. In the process of dealing with the rich guy, Mason interacts with overacting Victor Buono and deals with Captain Stubing (who is stuffed into a suit meant for somebody half his size). There's also a rampaging gorilla trashing the room of the now-dead rich guy. Mason manages to escape the monkey and rescue a former housekeeper being terrorized by the hairy silverback by throwing a few coins on the floor and staring at the ape with his manson lamps as he walks past it. Of course the ape isn't the killer and the story unravels from there, but the ape interaction? Shark written all over it.
Saw an episode of Brady Bunch recently too. The introduction of Cousin Fuckersludge. Little bastard looked like John Denver playing Benjamin Button. That was very sharkish too.
Just out of curiosity can you pinpoint other instances where a show jumped the shark and hastened its decline?
For Sopranos? It was the moment Vito popped up from between the construction worker's legs. Some of the greatest episodes in the series followed in the wake of that disaster of a scene, but the remainder of the series run devolved from that storyline tangent.