A lot of the endings being described are very different than the “bummer” ending in the movie in the OP. A random shock at the end like a bus suddenly runs over the protagonists is very different than the antagonists prevailing in exactly the way they planned to all along. Another horror movie that I think fulfills this ending type is Jeepers Creepers.
Another ending that maybe fits the OP: The Parallax View.
Tolkien coined the term “eucatastrophe” for “a sudden turn of events in a story which ensures that the protagonist does not meet some terrible, impending, and very plausible and probable doom” or “a massive turn in fortune from a seemingly unconquerable situation to an unforseen victory.”
It sounds like you’re thinking of situations where a eucatastrophe fails to occur.
I loved it.
Aren’t they just called tragedies?
One that seems to fit the OP: Arlington Road
rimshot/
Edit: Actually, this movie is probably too twisty to qualify for the OP’s requirements.
The ending to Two Lane Blacktop is an awesome artistic touch and apt end for the movie. None of the characters even had names, the driver, the mechanic, GTO, the girl, they were all burned out individuals with no place to be and no place to go.
When the driver takes off for the final run at the end, and the film sticks in the projector and burns away it symbolizes their burned out life. Maybe the driver crashed, maybe it was just another meaningless day on the drag strip. It was a very Sopranos type ending that could be interpreted however you want.
The ending of Monte Hellman’s Two-Lane Blacktop | Sight and Sound (bfi.org.uk)
It sure looks like the antagonists are going to just do exactly what they’ve planned in The Conversation; but, when all is revealed at the end, the twist is that the antagonists just did exactly what they planned.
For what it’s worth, I saw a version of Othello where they removed the part about Iago’s villainy getting brought to light; instead, Othello gets goaded into murder easy as you can say ‘reverse psychology’, and then suicide ensues, and then — well, the trusted advisor just gets the big promotion that he wasn’t overtly gunning for, as a subset of him pretty much getting away with everything, exactly as planned.
Strictly speaking, that maybe shouldn’t change anything in terms of whether that qualifies for this thread; but it sort of feels like it does.
Wouldn’t from Fortinbras POV in Hamlet, his plan to take over Denmark works far better then he could have hoped? Just strolls in almost completely unopposed and everyone is dead.
Not that it would have mattered if he showed up ten minutes earlier… He would have strolled in anyways. I want to see THAT Hamlet. The Monty Python and the Holy Grail ending to Hamlet
“What’s that? A foil? Thats a dangerous weapon. You’re under arrest son. Who’s in charge here?”
(Hamlet points at Claudius.) “Uhm…he is.”
“He’d kill us if he got the chance.”