Well, since my love for The Shining is really what started this whole mess, I should at least stand up to defend it here.
First off, full disclosure, I have not read the Stephen King book, so maybe having nothing to compare it to has a lot to do with it, but I think Kubrick really put together a masterpiece. Its patient, disturbing, from-your mind, not in-your-face horror. Of course, at the end, you have the chasing with an axe, trapped in a room, will-they-make-it kind of action, but it is in no way a slasher movie. We see the development of madness and understand the dreadful history of the setting. With a small cast, closed quarters, and the errie music throughout made for absolute creepy. And yes, Nicholson really sold the crazy guy, but I don't think it is just him.
Like say, I'm sure the book does a much better job of getting into the history and immersing the reader into the madness even more, but for me, the movie did a great job. I've said this before, but the trailer for this movie alone made my little sister cry and shake with fear.
I understand it's not the same for everybody.