I can sum up the problem with the movie World War Z: I am not a fan of fast zombies. 28 Days Later was just okay, but only for the visuals in the first half of the movie, not due to its bezerker zombies. Will Smith's I am Legend was legend fail. The only way zombies are even remotely plausible is if they have extra slow metabolisms. Otherwise they would just run out of food and calories and die (I know arguing science and zombies is a bit much, but good fiction has some plausibility in reality). And Brad Pitt has not done a good movie since...well...a while. A River Runs Through It was good.
The original novel.
At least Walking Dead Season 3 is better than last year.