What a fantastic movie! Vincent Price acts for the first twenty-two minutes with voice over only. No dialogue. A remarkable feat! The "vampires" who attack his home are a bit lame. However, his compelling presence makes this movie a joy to watch.
The Last Man on Earth is based on Richard Matheson's 1954 novel "I Am Legend." The basic plot is that a plague has wiped out most, if not all, of humanity except for Robert Morgan [Vincent Price]. The dead humans have come back as "vampires" and Morgan spends his days killing vamps and trying to find a cure for the plague, all the while wondering why he is immune to the disease. [Go, Buffy!]
If the plot sounds familiar, it should. The book was also adapted to film as "The Omega Man" in 1971 starring Charlton Heston and as "I Am Legend" in 2007 starring Will Smith. Personally, I prefer "The Last Man on Earth" over both of these later versions. "The Omega Man" is too hip for its own good and is mired in bad 70's clothing and too much talk of "the family" as if the infected were followers of Charles Manson. The "zombies" who inhabit "I Am Legend" are CGI disasters, looking more like cartoon characters. They move in ways that would be impossible for a creature that was once a human being.
If you've never seen the 1964 film, I cannot recommend it enough. Thankfully, it is now available as a free download and is in the public domain. I hope this will enable more people to see this wonderful film.
Download a copy of the film from Archive.org
For more info check out the film's entry in IMDB.