A lot of people say Stephen King is weak on endings, but I never saw it as a consistent problem. So just for fun, here's a quick and incomplete survey to see if the complaint holds up.
Since a good ending should be memorable, I won't consult any material except for the wiki bibliography. I shall keep spoilers to a minimum.
Carrie: It's a short novel, and the ending fits it very well. Not so sure about the whole "Meanwhile, over here" thing, but it also fits in with the newspaper infrastructure.
The Shining: Y'know, the first time I read this, the climax really annoyed me. I was going "Not the [SPOILER], how bloody obvious", or words to that effect. On a reread it struck me as really fitting and powerful, so I'm going to stick with that.
Rage: the ending where Stephen removes it from circulation completely is a bit sad, but the novel itself ends perfectly well.
The Stand: I promised I wouldn't go look up stuff, so I _think_ the whole Hand of God thing is fairly momentary and understated. That seems to be the main complaint, which does ignore the fact the presence of the [SPOILER] is set up over the entire book (bumpity bump). I had a greater problem with the huge amount of pages between that and the actual end of the book, which may just be in the expanded edition (like Dark Tower 1, I prefer the lean mean original). The bit on the beach seems a bit dodgy too.
The Long Walk: is very good.
The Dead Zone: is brilliant!
Firestarter: I liked this ending a lot. Despite similarities with Carrie and Rage (young person much put upon), the ending goes in a completely different direction which fitted in with the more expansive political focus.
Cujo: Sadly, I mostly remember the movie ending, but I'm pretty sure it's similar and I don't remember having any problems with either.
The Running Man: rather different from the movie, and pretty neat. It would have a bit of a different effect these days.
Christine: the whole final battle seems fine, and I remember liking the epilogue. Was there some problem with Gaunt being a bit of an anticlimax? Hmmm.
Pet Sematary: not unexpected, but very good.
The Talisman: I remember it being good, mostly the melancholy bits.
The Mist: I'm cheating on criteria a bit, and my memories of the printed version are very hazy. It must be said that the movie ending is really ballsy, and I thought they sold it convincingly. Others disagree strongly.
It: the archetypal disappointment -- with It's final form and with an undercurrent of squickiness at the, um, group bonding. I didn't mind either particularly at the time, although I understand the arguments. Strangely, I think The Dark Tower series actually improves this ending, by putting it all (especially the Turtle, ain't he keen?) in a wider context.
Misery: Um. Good? I'm sure I should remember more of it.
Needful Things: perhaps it would have been better if the ending had done what King promised it would. On its own, it was all a bit unexciting.
Gerald's Game: The ending of this is really weird. It's like an anti-twist, which was sort of interesting, but not really effective. (I see they are starting to film it. That just seems uncomfortable for all concerned.)
Insomnia: Mostly I remember some aircraft wreckage decapitating some noted feminist!? Not sure that was right at the end though.
The Green Mile: The ending of the main story was pretty much in keeping with it all. I seem to remember a neat melancholy epilogue as well.
Bag of Bones: The ending (ie, the actual bag in question) is about the only thing I do remember clearly. Sort of made sense.
Hearts in Atlantis: Brilliant! I loved this greatly, especially how it all ended up (and have railed at the movie for betraying that ending on more than one occasion).
Black House: I was liking this, until they actually enter the Black House itself, at which point it all went downhill rapidly -- since that's the last third of the book or so, I'm not sure it entirely counts as 'the ending'.
From A Buick Eight: I remember being a bit annoyed at the final bit, which could have been a little less pat considering the subject matter. Still, pretty good.
The Dark Tower: the whole ending of this series was rather disappointing to me, and by that I mean the last few books. Gathering the ka-tet was wonderful; giving them appropriate drama and challenge once they were together was trickier. However I will still defend the actual last page of it all as most excellent.
The Colorado Kid: Oh God, all I can envisage is Haven -- and I hope that ends well. From memory I had the same complain as Buick Eight, only more so; I don't think Sai King trusts anarchy, even when it is his main theme.
Cell: The gets a special mention because Steve came out later and 'explained' the ending. That was not only unnecessary but may even weaken the book. Anyway, mostly fitting for what it was.
Under The Dome: the explanation of what is really going is just... silly. The very definition of arbitrariness. But I do really like the entire direction of events under the Dome (and especially now in comparison to the TV show) so I am favourably inclined to where it ends up.
11/22/63: I think this is an alright novel that ties up a lot of loose ends much better than I was expecting it too -- and then undermines it all at the very end with political theorising that is entirely beside the point. (And for the record, I don't think this improved It as much as the Dark Tower did.)
The Wind in the Keyhole: Did this even have an ending?
Doctor Sleep: when I get there... Is pretty good so far.
It all goes downhill a bit at the end(!), but Hearts in Atlantis really is the last book of his I loved fully and joyfully. However, there are more than enough excellent books with excellent endings to be getting on with. He is not much into radical endings that make you rethink everything, and sometimes the action is a bit arbitrary, but I also reckon he rounds out his events with a minimum of loose threads and deus ex. The Dead Zone strikes me as the cleverest ending (and a clever book in general), and there are a fair few melancholy epilogues I am inclined to like.
None of which will probably sway the common perception, but it's nice to at least justify my own opinions.