@IcyLucario

The "I didn't want to be predictable, so I ruined a good ending by subverting expectations when the good ending actually WAS the better ending" ending.

@PlasticTierHealer

The easiest way to make sure they don't reach the end and decide they wasted their time is to make it abundantly clear they're wasting their time from page 1. You can't lose.

@chipnterry

The main reason why Alice in Wonderland's ending worked is because she experienced the character growth even though it was a dream.  She returned to the waking world much more confident and mentally strong.  She had gained all the qualities she had lacked at the beginning before the dream started.

@timwideman9805

I once read a really amazing book. Every page had me wishing I’d written it myself. But in the end, it was all a dream; I just woke up and there was no book at all. Worst part was, I could remember how the book had made me feel, but the specifics of the plot faded from my memory before I could write anything down. Worst ending ever.

@oremfrien

I would push back a little on Rule 8: A predictable ending can be acceptable if we are really invested in the specific way that the characters get there.

@mariokarter13

In my experience, the worst endings tend to come from the author attempting to outsmart the audience. GRRM actually said something to that effect a few years back. "You set the story up so that the Butler did it, you place all these clues that the Butler did it, but then someone on the Internet figures out that the Butler did it, so you change it so that the Maid did it and destroy the entire rest of the story."

@Hrafnskald

One More: The Happy Ending Fakeout. 
This is when the author writes a happy ending that is satisfying, then destroys that happy ending in the final pages, undoing everything the characters have accomplished. Seanan McGuire's "Be the Serpent" is a great example, where you get a bitter sweet but happy ending, then it is ripped away in the last two pages in a reverse Dues Ex Machina where the bad guy wins in a way that was explicitly stated to be impossible. The TV Show How I Met Your Mother is another example, showing Ted and the Mother meeting in a satisfying way, then ripping apart their happiness, revealing she was dead, and showing all the characters reverting to their older, less kind or honest states. 
If you give a happy ending, don't rip it away at the very end.

@thatoneXman

In regards to unearned happy endings, the same can be said vice-versa; Nothing is more unbelievably deflating than a sudden twist downer ending, especially if the story wasn't building towards it in the first place. Personally I'd rather have an unconvincing happy ending over a sudden unbuilt downer.

@hasindudinushan1988

The worst kind of endings for me are those forced sad endings. This is specially present in horror and it's become a new norm. A really good example is "The Autopsy of Jane Doe". The story goes through an emotionally redeeming and a thematically satisfactory character arc only for it to completely collapse to pieces in 5 minutes.

@gabrielafonseca4034

I'm an editor and writing coach, and what I've been seeing in younger authors is, since they grew up on Harry Potter and other multi book series, they want to do the same... So they write a giant book only to end it in a cliff hanger that teases the sequel. I have to explain to them that no reader is going to appreciate reading six hundred pages and get no resolution.

@gonaye1

0:40 Edit: HBO actually wanted more GOT seasons and were prepared to pay for it, but the showrunners decided to race towards the ending so they could focus on an upcoming Star Wars film deal (a deal they eventually lost anyway)

@Ari666Dei

the tv show Merlin has the worst ending in history. 5 seasons of “it’s your destiny to help Arthur become a great king”, 5 seasons of Merlin saving Arthur while hiding his magic, and then in the last 20 minutes of the last episode Arthur finds out, they never elaborate on it, and then Arthur dies, not even fulfilling the prophecy that they mentioned since episode 1. i cried for days

@isaacmahoney7406

One ending you didn’t mention: “I’m a crazy Unreliable Narrator who has been misleading you the whole time.” It often leaves me feeling cheated.
This can be done well (such as Fight Club), but often a mystery novel simply revealing that the narrator is crazy is such a betrayal.

@alpheusmadsen8485

With regards to "unearned happy endings", one of the things that drives my wife nuts in romance books is how often a near-abusive treatment leading up to the big reveal is brushed off, everything is ok, and the relationship is going to be a "happily ever after!" -- as we've talked about this, we've come to realize that the biggest problem is that the redemption isn't earned!

@annika5893

Agatha Christie's Murder On The Orient Express has the perfect double twist at the ending. The one you mentioned, that everyone was in it together. But also that the passangers on the train managed to get Poirot, who has an impeccable sense of justice, to side with them and lie to authorities that even he had no idea who committed the crime.

@lucidragon5260

I appreciate that you not only showed examples of the endings done terribly, but also the endings using the same trope that worked well. It helps add nuance and explain better what exactly it is about the bad endings readers didn’t like

@rollintroagain2851

The best “bad ending” I ever read was as a kid. From the book The Name of this Book is Secret. The author stops the story, and admits to you he’s horribly bad at writing endings. The rest of the pages are lined pages with prompts like “when he said goodbye to his friends, he…”

The part that made it good in my opinion is twofold. One is that in the rest of the series, when he referenced the ending of the first book he’d reference the fact you helped him make it. The second is that, later in the series, the plot twist is that the main character’s nerdy best friend is the author. It reveals long after the fact that the reason he couldn’t bear to write the ending is because that was a sad memory for him- saying goodbye to his friends.

@jeffersonian4

To add to the point about Alice in Wonderland: the other big point is that it being a dream does not wipe out the meaning of the story. Alice still remembers her adventure, and was still changed by it, despite it being a dream.

A huge part of an audience's frustration with "it was all a dream" is that it invalidates the experiences the characters had, the story has no consequences or meaning. In Alice's case, her experiences continue to be valid and have consequences for her, in spite of the revelation it was a dream.

@rogerostrander3292

"It was all a dream" can be done well if the main character has changed as a result; I think "Scrooge" is probably the best example, he's overwhelmed to find that his unmourned death is not written in stone, that there's still time to find redemption.

@TheOneGuy1111

You forgot the worst one: No Ending.  Abandoning your ongoing story leaving readers denied any sort of conclusion.