land of the dead (2005)

aka George A. Romero's Land of the Dead.
Zombies have overrun the earth, whilst people live in well fortified cities. The rich, including Kaufman (Dennis Hopper), live it up in their penthouse apartments, literally looking down on the poor. But the zombies are getting smarter and the population are growing resentful. In the middle of it all is Riley (Simon Baker), who leads a team supplying the city by foraging outside, using an armoured truck. One of his team steals the truck when Kaufman betrays him, forcing Riley to attempt to get the vehicle back. All the while the zombies keep probing for weaknesses in the barricades.
Another Romero, another alagory about society and it's dog eat dog ways, but this time he ups the action and keeps the film a taught 90 odd minutes, and its all the better for it. Even a few old friends from previous movies turn up, including Blades from Dawn of the Dead.