The Last Man on Earth

Vincent Price plays the titular protagonist in this 1964 film based on Richard Matheson's 1954 novel I Am Legend.  Price is the lone survivor of biological warfare which has turned the populace into ghouls.  Although the ghouls are as much vampires as zombies, George Romero was obviously inspired by the plot and particularly by the scenes of shambling undead trying to get into Price's fortified bungalow.  Price does well portraying a lonely, half-crazed man grimly hanging on against the odds, but the film overall is a little slow and lackluster.  The similarities between it and Night of the Living Dead are interesting, but for entertainment, read Matheson's novel instead.  And don't bother with the Will Smith version, either.