Another Titan has fallen- George Romero, the father of the modern zombie/ghoul/living dead horror genre, has died, but I suspect he'll be back. Romero's films, made on tight budgets with casts of unknowns, are notable for their political content as well as for their gore. The original Night of the Living Dead was notable for featuring an African-American protagonist, and while the political message is in the background, the practically subliminal racial tension is a factor in the dynamics of the group almost as much as the tension between the living and the not-exactly-dead. The ending of the movie is one of the great shocking twists of cinema history.
Dawn of the Dead, in my estimation Romero's grand opus, is a savage satire of consumer culture, as rival groups of survivors (particularly cops and outlaw bikers) ensconce themselves in a mall to withstand a siege by ghouls. The breathers and the shamblers are all obsessed with consumption- the undead at least realize that humanity is the product.
The Tor article I linked to is an essential read for Romero fans- the sheer ubiquity of the tropes the Romero started served to drown out the oeuvre of the man himself, leaving little room for an auteur who preferred to work with modest budgets and practical effects.
One thing that I have to note about Romero is that he had a sense of humor, albeit a grim one. One particular scene comes to mind, in which the female protagonist's brother tries to scare her:
My favorite line in any of Romero's movies is the deadpan-snark description of the undead uttered by the character of the police chief who is leading the local response to the zombie uprising:
Night of the Living Dead, surprisingly, is in the public domain. It's a bit gruesome, but not over the top like some modern splatter films. Even if you're not a horror movie fan, it is an interesting watch, because of its genre-defining status. Just keep the lights on, because George might be coming to get you.