Judging Amy.
Maybe not so much a cliffhanger as opening the door for a spinoff.
She retires as a judge and seems to be considering a run at a senate seat or something.
She ended up a doctor in a boutique practice in California…duh!( Oh yeah and slept with her ‘mom’s’ brother Tim Daly Hee)
Maybe not so much a cliffhanger, but in the final 3 episodes of Maude, Maude Findlay somehow got herself elected to Congress. That was supposed to be a reboot for the series, but Bea Arthur became disenchanted with the project, and dropped out.
Undaunted, the producers cast John Amos as the newly elected Representative. However, Amos also dropped out.
Not willing to let go, the producers then rewrote the script to focus on the internal politics of a university and cast Bill Macy (Maude’s husband) as the lead. The result ended up on the air, but was canceled after four episodes.
Sorry… do you have an apprentice? 
I don’t know if it counts, but. apparently, the execs thought Gilligan’s Island ended on a cliffhanger. They had to devote two movies to resolving how they got home.
I remember that episode. The dance was a huge success - too huge. Jason Bateman get a call for the Dregs of Society (IIRC) to play Madison Square Garden.
Episode ends.
As I recall it, Sledge Hammer actually ended up having a second season- set as a prequel.
I’m not sure how to classify Red Dwarf… Series VIII indeed ends on a cliffhanger, but the recent 3-part special begins nine years later. Shame it turned out to be a 3-episode long remake of the Series V episode Back To Reality. Even so, I rather enjoyed it, FWIW- if it was nice to see the lads back together again. 
Blackadder Goes Forth ends with a semi-cliffhanger. It’s implied everyone gets machine-gunned, but… well, Baldrick did have a cunning plan up his sleeve, apparently. 
Well, I missed that. ??
John From Cincinnati sigh
Blackadder: everyone dies at the end. It’s not a cliffhanger.
The CBS show Now and Again was awesome. It featured John Goodman getting killed in a subway accident and having his brain brought back to life in an artificial body (played by Eric Close) designed to be a super-soldier, with super-strength and super-speed (and super-healing). But he could never contact his wife and daughter, or the scientist who created him (played by the guy who played the president on season 1 of 24… Dennis Haysbert or something?) would kill him and replace the brain with somebody else. It lasted one season and was cancelled on the ultimate cliffhanger. Grrr.
Also, Sir Arthur Conan Doyle’s The Lost World was great schlocky fantasy fun that reminded me vaguely of Kevin Sorbo’s Hercules series and Xena: Warrior Princess. It lasted three season before a dispute between some of the producers and the studio (or something like that) caused the fourth season to be delayed … and delayed … and delayed … and finally years had passed and there was no way it was ever coming back. It also ended on an ultimate cliffhanger. We eventually got a 64-page synopsis of the storylines that had been planned for the 4th season, but it just wasn’t the same as actually having the 4th season made … there’s no Jennifer O’Dell in her self-designed leather bikini-and-miniskirt outfit, for instance.
Right before they go over the top, Baldrick says something like “I have a cunning plan to get us out of this” and Blackadder says “Well, whatever it is, it will have to wait” before he wishes everyone good luck and gives the order to commence the attack.
I know it’s strongly implied that everyone gets machine-gunned, but there is an “out” there should they have decided to make make Blackadder On The Western Front Christmas Special.
(They talked about doing a series called Red Adder, with Edmund (or a relative, more likely) as a Commissar in Russia during the Russian Revolution.
Vanished.
Fuck you Fox, fuck you :mad::mad::mad::mad::mad:
Everyone but Baldrick dies at the end of the first series too don’t they, so continuity is not a problem.
And the second. It’s only the third series in which Blackadder survives (as an ersatz George IV).
And the one-off specials.
This is the show I was just about to mention.
“They’re coming!”
“Who?”
“Men with guns!”
Damn, that was a kickass season finale. A shame it was the series finale.
Just gonna spread the gospel as I know it here; Knauff had the entire storyline as a single season (and from some of the canon he’s dropped, it was a heck of a story), but HBO said, “Oh no, this needs to be strung into 5 seasons so we can get people really excited and hooked on it!” Dutifully, Knauff put in some other plotlines and filler, so that 5 seasons could be reached.
Then they pulled the plug at the end of season 2.
Made me quite mad, but as I’ve often told people, “If you cut out the last 5 minutes of season 2, it’s actually pretty self-contained. Not all of the mysteries are solved, but it comes to a decent ending.”
Yep. The producer of the show, Alan Spencer, didn’t expect Sledgehammer to be renewed, so Season 1 ended with the nuke going off. When the show was, in fact, renewed for one more season, the writers worked their way out of it, as you say, by starting Season 2 earlier. I seem to recall that the title screen for at least the first episode of Season 2 read: “Sledge Hammer! (The Early Years)”.
Well, we can add Medium to the list. The show was recently canceled to make room for Jay.
Allison has a brain tumor, she has surgery which removes most of the benign tumor but she suffered a stroke before the surgery and the show ends with her in a coma. The doctor tells her husband that they have no way of knowing if she will ever wake up. The final scene of her in her hospital bed has “To be continued” on the screen, oops, no it’s not.