The Mist was one of the first Stephen King short stories I ever read and it definitely had a huge impact on my creative life from a young age. In late middle school or early high school I wrote a short story called And the Shadows (horrible title) about a group of Entertainers stuck in a nightclub while mysterious creatures hidden in the shadows of the night picked them off one by one. It was very much a Mist homage.
The King story and the Frank Darabont movie take place mostly at a grocery store in Maine. When a man and his son go into town for supplies following a rough storm, they find themselves trapped inside the store they visit by a thick fog from which no human emerges. If you wander into the fog, you are pretty much dead. There are all sorts of Lovecraftian creatures lurking inside to tear you apart and, without the aid of your vision, you are all the more vulnerable. Of course, the mist isn't the only thing to be afraid of as the trapped and panicked shoppers begin turning on one another thanks to a busybody religious zealot who thinks sinning has caused the mist.
It is hard to screw up a premise this strong and Darabont does not drop the ball. The scenes with various people trying to explore nearby stores or just get to their cars are very nerve-wracking. While the religious zealot (played wonderfully by Marcia Gay Harden) is painted in broad strokes, the intended effect of the audience kind of hating her still works. Thomas Jane is very strong in the lead role as a father watching out for his son in the middle of a very bad situation.
Of course, the controversial part of this movie is the bleak, bleak ending. I mean, I can't even begin to tell you what a downer it is. The short story ended with frightening ambiguity but the movie decides to let us know exactly what happens to everyone. If you can deal with a certain amount of soul-crushing (and not in any way you are guessing right now), check this out. It is one of the better King adaptations and I promise some solid scares.