This is, by no means, any sort of endorsement of any of the film/TV/radio-drama adaptations of this work—all of which either entirely miss what gives this story its lasting power, or convert a fundamentally profound work about kitchen-table American politics (i.e., the only kind that actually matters) to a moderately stupid and lazily nihilistic creature features.
Read the novella (which is also the first story in Skeleton Crew—a whole book of classic King shorts that costs just a couple buck more than the standalone novella—and is bootlegged here). Ignore the monsters and the titular mist; watch the people. And never lose sight of the final word in the story.