--Dawn of the Dead
The set up is familiar. Confinement. Warring factions. Hordes of zombies waiting outside. This is the Night of the Living Dead formula (some might call it the Rio Bravo formula). It has proven to be remarkably durable. You can change the meaning of the whole enterprise depending on who your characters are. One of the best explorations of this formula can be found in John Carpenter's second feature, Assault on Precinct 13, in which you have cops and killers confined in a besieged police station. It's not a zombie film, true, but it's filmed like a zombie film. Because everything in genre comes full circle eventually, even at second hand, we find Assault on Precinct 13 regurgitated in the 2009 French zombie film, The Horde (directed by Yannick Dahan and Benjamin Rocher), a film that removes the Assault on Precinct 13 narrative from the Hawksian tradition and returns it to the realm of the zombie film full on.