Children of Men and The Thing both have slower final scenes that allow one to catch their breath after the climax. Ambiguous is not the same as abrupt, at all. Even stuff like Halloween, or Friday the Thirteenth or Carrie, I'm not sure, since they have endings, then"...or is he??" moment, which can be viewed as a coda. They could have run after the credits and you wouldn't feel like the movie "just ended".
In terms of what I feel is abrupt, I think genre plays into it a fair amount. I'd say the dividing line is whether I'm surprised when the credits start rolling. Birdy and Reservoir Dogs certainly had that effect, whereas Halloween didn't because that seemed like a logical beat to end a slasher movie on. Then there's stuff like Chinatown or Pulp Fiction, where they don't really cut to black abruptly, but the feeling is there because it seems like there could be easily be another scene or two of denouement. It's not about cutting to black, it's about the proximity of the climax to the final shot.
Although a great one that flies in the face of everything I just said is Iron Man, which plays off its genre conventions brilliantly.
Quote:
Originally Posted by
avoideverything 
American Werewolf in London ends pretty quick. Just before the most inappropriate closing credits song ever.
Sidebar: more inappropriate than "15 Step" closing out Twilight? That was a real headscratcher for me.
Edited by Schwartz - 10/4/11 at 9:09am