You know-Where the characters from one show visit the characters from another show as a ratings stunt? As a fan of bad television, I have seen a few of these, but the worst I can remember was when the z-grade syndicated action series “Nightman”(your typical “jazz saxophonist gets hit by lightning and gains magical powers” show) decides to do a cross-over with a series that had been cancelled several years before…and decides to go with the infamously bad NBC series “Manimal”(a show so bad it went on hiatus after showing only three episodes!). Maybe they thought it worked like math-a negative times a negative creates a positive? Instead what you got was Bad Squared.
I thought the 24/Simpsons crossover was really bad, especially when both their Critic and X-Files crossovers are such iconic episodes. Just seemed like late season Simpsons bad writing though, too many jokes thrown in at once hoping one sticks. Plus they brought back Kiefer Sutherland later on to play the exact same character under a different name which was weird.
There was a sort-of “Cheers”/“ER” crossover episode where George Clooney and Noah Wylie, as a pair of doctors, show up at the bar. Except they weren’t their characters from “ER” (which would have been stupid anyway since ER is set in Chicago). Not sure what they were thinking with that one.
ETA: I guess it was more “stunt casting” than a crossover. Never mind.
Though it was no where near as bad as some mentioned (Col Klink in Gotham! Oy ve!) L&O Criminal Intent episode “Contract” had Mary Shannon from In Plain Sight show up for no real reason. She was there, it wasn’t played for laughs, she didn’t do anything that any random actor couldn’t do, she barely interacted with the main cast, and she was gone in about two minutes, never to be mentioned or seen again.
It just functioned as an in-episode plug for the other show, and nothing more. If you’ve never heard of In Plain Sight, the whole scene would be wasted on you.
I would also nominate the one between Bones and Sleepy Hollow. I actually was a big fan of the latter and, although I had given up on the former, had followed it for several seasons. And I certainly appreciated the network’s attempt to give Sleepy Hollow a shot in the arm by connecting it to a more successful show. But the two shows were so different in tone that it was a perplexing fit. It would have worked much better if they had found a more magically inclined show for Ichabod Crane and pals to wander into.
William F. Buckley’s old PBS show Firing Line I thought filled in quite seamlessly with BJ and the Bear in a five-epi “mini-series” that for some didn’t really catch on. Lots of sheriff/hitch-hiker action, with occasional rhetorical respites usually delving in US economic and foreign policy.