Brady Bunch grew some stubble from the second season onward. That first season lacks in classic Brady episodes and that Brady grooviness that’s parodied in the movie.
MASH jumped the shark for good around season 7 when Honicutt grew a 'stash and donned red suspenders. Season 6 with the arrival of Winchester was okay, but mainly just the Winchester episodes. The rest weren’t much better than season 7 which was perhaps the worst season of all. Season 8 had a couple worthy episodes but the subsequent Klinger as company clerk years were better left undone.
The Twilight Zone seemed to have a solid run sans shark jump.
The Next Generation and Deep Space Nine both Grew the Beard.
So did Mighty Morphin’ Power Rangers. Actually, there were some early Season 1 MMPR episodes that were more tolerable than some early season 1 TNG episodes. (I’ll take “Day of the Dumpster” over “Code of Honor” any day, thank you.)
Older shows:
I fully agree Dick Van Dyke never jumped but the went out on top after only 5 great seasons by their choice.
The Odd Couple is not aging well but it never jumped.
**WKRP **did no jumping as CBS killed it before it got the chance. The show was still getting better in my opinion when CBS cancelled it. (New WKRP does not count)
Barney Miller had a really long run without jumping. Probably the longest sustained brilliance.
I think **Cheers **& **Seinfeld **both jumped. The characters became caricatures by the final seasons. Still funny but not the great shows they once were. I know for Seinfeld I couldn’t stand George or Elaine at all by the end. Cheers’ writing just got weak. They were mostly out of ideas, like MAS*H.
**Simpsons **went 10-12 without jumping which is amazing but hit the skids a few years but has come back to being a pretty good show again. It seems like the movie revitalized the show.
On that note, I would say that **Futurama **has still not jumped the shark.
