When you don't expect much from something, the greater the possibility of being pleasantly surprised. I didn't expect much from The Crazies. In fact I went in with the film already having three strikes against it: I don't like horror films, I hate remakes, and director Breck Eisner's only other film was the lame Sahara. But wouldn't you know it? The Crazies is a pretty good film for a remake of a horror film directed by Breck Eisner.
What makes this remake better than most is that the movie almost begged to be remade. This original, created by zombie master George Romero, was sandwiched between two of his Living Dead movies. It's one of his lesser known works, which means that, even as a remake, it comes across as something new. The filmmakers also didn't do a straight up remake. A lot of remakes tend to just throw money at an old idea and hope the audience won't notice. Eisner, along with writers Scott Kosar and Ray Wright, not only change locations, but add new dimensions to the film. The original had an "us against them" mentality, with the townspeople going against the military (a product of Romero's obsession with post-Vietnam politics). This film dispenses with that and gives us a group of heroes fighting against not only the military, but the psycho townspeople affected by the germ seeping into their water supply.
It also doesn't hurt that they have a lot more money to work with than Romero did. This isn't one of your regular "made in the abandoned lot out back" horror films. This movie looks great, and the visuals allow the scares to be more potent. It's a rare film indeed, and does what a remake should: takes what could have been a great idea and turns it into one.