George Romero's Land of the Dead is not the best movie in the Dead zombie franchise. It is an action movie with zombies than a horror movie. Lots of stuff gets blown up, lots of zombies get their heads shot off, and lots of people get killed and eaten.
Simon Baker and the always dreadful John Leguizamo play two good guys who go around killing zombies as they scavenge for supplies on which the people in the fortified city live. The city itself is owned and operated by Kaufman (Dennis Hopper). At its center is a skyscraper / mall where all the right people live in comfort while the rest of the city lives in poverty.
Land of the Dead begins on Riley's (Baker) last day of active duty before he retires up north somewhere. His second in command, Cholo (Leguizamo) is eager to be the new boss but also has a few deals going on on the side in hope of making it into Kaufman's inner sanctum.
Problem is the zombies have a leader and are actually thinking things through and acting as a group. This allows them to breach the city. Riley and his associates try to prevent the zombies from getting control of everything.
Land of the dead is really big on action movie style violence to the detriment of the horror factor. In fact, you could replace the zombies with any kind of end of the world bad guys and you'd have the same movie.
Land of the Dead is mildly enjoyable.