The last 15 minutes or so of 8mm. Up until that point, I liked it. But then Nicholas Cage turns into Charles Bronson in Deathwish and I hated it. I guess I was hoping for a really dark, depressing ending.

For me it was the Disney Blue Fairy that showed up shortly thereafter. But like you a lot of people hated those aliens and gave up on that turgid movie at that point.

Just one thing though. They're not aliens. They're advanced mecha. Blame Spielberg for making them all alienesque and confusing audiences. That was dumb. I'm just glad he tried to make Kubrick's "AI" instead of trying to make Kubrick's "Napoleon." Yikes.

I like Salman Rushdie's reason for hating the ending of "The Wizard of Oz." In his brilliant little book for the BFI on that movie, he says that he sees Dorothy's journey as being all about venturing out on her own, escaping the dreary gray oppressiveness of life on a Kansas farm with her aunt and uncle, kindly though they may be. For him, the ending represented a cop-out, the whole "no place like home" thing working against the "I am becoming an independent woman" adventure Dorothy had staked out in Oz. A bit intellectually overworked, but he's got a point.

I mostly dislike The Exorcist "version you've never seen" because it stupidly tries to make the existence of Pazuzu in the household more literal and real (with the CGI "evil face" superimposed on the oven hood and all) whereas in the original cut, nothing is fully explained, leaving the movie to work on numerous psychological and metaphorical levels rather than being a mere literal possession story. On the other hand the added scenes with the medics are good and the "restored" ending is okay I guess. I dunno. No more "redux" versions, please, unless the theatrical was truly butchered à la "Blade Runner" or "Once Upon a Time in America."

I can't really think of one particular movie off hand, BUT what really kills ANY movie for me is when they try to tie up all the loose ends and sub plots via "it was all just a dream". This is 99.9% of time just writers being lazy, or really unoriginal.

The Pod Racing Scene.
Any time a movie has a long, scene that goes on way to long we refer to it as "this movies pod racing scene".

bong worm in freddy vs. jason...

I think a lot of people would agree with that, makes you wonder if Mr. S screened the film before he released it. I was expecting it to end at the underwater sequence as you mentioned, but just as I was ready to leave the theatre... WATERY ALIENS!!?
He's just gotta have a happy ending...

Another film that was ruined like this (Spielberg again) was the new Indy film.
WHATS WITH THE ALIENS ALL THE TIME? It's just ridiculous. I can accept Spielbergs Close Encounters because it's about aliens, I just hate when they 'pop up' to fill a plot hole.

The closing title card in Paranormal Activity really destroyed the whole thing for me.
I was quite happy to play and get lost in that film, until that

One of my favorite movies of all time, Conan the Barbarian (don't laugh). When the woman comes back as a spirit to save Conan. Like Ahnold the Barbarian needs anyone to save him, let alone a ghostly woman. Seriously. They just destroyed the whole point of Conan the Stud. If it wasn;t for this scene, this would be the greatest movie ever made, hands down!! ( ) Despite this tragic flaw, I still have to love the whole flick, especially the killer score.