Jump the shark

• David Addison and Maddy hooking up in Moonlighting
• Fight the Future - the movie point of the X-Files storyline
• The end of season 4 of Babylon 5, when the Shadow Wars end

There are even specific categories of how to jump the shark. For instance, the main characters can hook up, as in #1 above. Or a show can resume after a season break - but with a different actor playing a continuing character. Or perhaps, like in Dallas, an entire season can be declared to have not happened! Thanks to the world wide web, there is a whole website where you can discuss, research and sound off on when shows jumped the shark. It is at: http://www.jumptheshark.org

• The absolute worst offender was that godawful red headed kid they brought in on Diff'rent strokes. Arnold had quipped "what you talking about Willis/Mr. Drummond/Kimberley/Pearl?" too many times and was running out of cuteness quick fast in a hurry. Did anybody in the world not want to murder that kid?
• Wasn't that exact same kid also on Webster? Webster was a pretty bad offender in the cutesy department, ("I know I could call you Catherine, but I prefer Ma'am because....it sounds like Mum." Ahhhh. Not to mention the guy who dreamt he was eating a giant marshmellow and when he woke up, his pillow was gone), but I'd rather twenty four hours of the Olsen twins than two minutes of that redheaded stepchild. (Does anyone remember his name by the way?)
• Speaking of the Olsen twins, as if they weren't bad enough, when they grew up, the writers of Full House decided it was time for Uncle Jesse to have twins!?!?Puleeeze.
• My all time favorite sitcom was even spoiled by a (not at all) cute Jheri curled little brat, called Ritchie. Oh no, how could they do it to Family matters? I mean, if Urkel, Carl and that horny grandmother (why'd you turn on my oven if you not gonna cook?) couldn't hold the fort, what made them think Ritchie could?
• Even the writers on Friends get lazy from time to time. What? That stupid monkey!!! Marcell. Aw well, they had two good seasons.

I'd be happy to add any more that anyone can think of, please /msg me.

Jumping the shark is a good way to put it for another reason: the fact that a shark's dorsal fin has this looong leading edge, and then...drops off. It's like when you've got this TV series, or group, or author, or actor... (my favorite is Sting), that has a good career, maybe a great one. They can do no wrong! You're confident, even complacent about how they'll always be there, doing that thing they do, better and better... and then... nothing. They screw up, not just a little, but bigtime. You feel embarrassed they're still around. Your old favorites are still there, but there's something... missing somehow when you know that instead of there being "more where that came from," or even "what if there were more", but that there is more. And more, and more...

Or they leave, and come back...as happened to me with Patti Smith. PS 70's? Golden. Pure unalloyed ecstasy. She leaves showbiz for anonymity in the Detroit area. Years pass, with everyone speculating on the might have been. Comeback time! Smith fans rejoice! Only now, Robert Mapplethorpe is dead, Fred "Sonic" Smith is dead, the crew is older, she's off drugs... and the wacko politics (a paen to Ho Chih Minh?) no longer seem deep or amusing.

Actual "jump over the shark tank" gestures can sometimes restart an artist by repurposing them into a different direction, but for some, it's too late.