The Crazies, a remake of a seldom-seen 1972 George Romeo film, is about a small town whose inhabitants drink tainted water and become deranged. The movie is slick but still terrifying, relying not only on wacked-out effects but also on unadulterated suspense to really rattle your nerves.
At a Little League game in Ogden Marsh, Iowa, a man wanders into the outfield carrying a shotgun. When the man raises the weapon, Sheriff David Dutton (Timothy Olyphant) shoots him dead. But the man wasn't drunk, he'd just gone crazy. Dutton investigates further, with the help of his deputy Russell (Joe Anderson), and discovers that a plane carrying a deadly cargo has crashed into a nearby creek, thus poisoning the town's drinking water.
From there, events quickly get out of hand, as anyone who'd drunk water from their taps becomes first listless and unresponsive, then mumbly, then completely unhinged. But that's only the beginning of the nightmare for the town, which is then surrounded by a military force bent on containing the virus by any means necessary.
This is only kind of a zombie film. I mean, no one's dining on the flesh of their living compatriots, there's no shambling, and mindless killing. (There's plenty of killing, but the afflicted people still have the capacity for reason.) One thing I liked about this was that precious time isn't spend trying to discover the reason for everyone's behavior; attention is focused on the survivors and how they react to what's going on. I also appreciated that at no time does anyone, even the sheriff, have this superhuman ability to know what must be done and how to do it. Dutton isn't a superhero, he's a sheriff.
Another thing that helps a lot is the pacing. Too often, things either move so quickly that you can't figure out what's being done to whom or too slowly so that the suspense angle becomes the boredom angle. This is crucial for a horror film, which basically trafficks in suspense. Director Breck Eisner keeps the action coming without holding up the story (e.g., no drawn-out standoffs when it would look implausible), and there are plenty of creeping-up-on-you moments to choke twelve cows.
Olyphant looks a lot like a younger Bill Paxton here, and he's a good fit - Sheriff Dutton is a solid leader, but he's not an improbable one. He's the kind of guy who rises to the occasion, not surpasses it completely. If you're looking for a movie where the hero is always armed to the teeth and subsequently never gets much more than a scratch on him, this isn't for you. Dutton has to constantly fight with his own instincts and change his attitude during the course of the movie (save everyone, save his wife, save a few people, save himself).
People who make horror movies know they're making them for a pretty select audience. Lots of people don't like horror movies at all, and those who do are somewhat picky about them (particularly with so many big-budget ones from which to choose), so standards are high. It's important to grab that core audience, show them something they haven't seen or haven't seen done particularly well, then smack them upside the head. Classic horror films used the horror of the unseen to great effect, and more-recent genre films try the same thing. (One reason for this is that we've become inured to in-your-face slasher films, because the anticipation of the slasher doing his slashing has largely been eroded. But that's a digression right there.
Basically, if zombie movies in general are your bag, you should love The Crazies. (If you don't like any horror films regardless, there's no way you should see this.) The Crazies is effectively scary, mixing human emotions with raw blood and gore and endless edge-of-your seat thrills.