Beginning of the End (in same playlist as the original Brave New World, but separately listed here):
Day of the Triffids. This scared me as a kid. Now, it makes me think of that Dr. Who episode with the giant Daffodils. Only here, they are snapdragons. LOL! Stars one of my fav musical actors, Howard Keel. Sorry, this is only in 480p:
The BBC remade it into a series starring John Duttine (who played the apostle John in Jesus of Nazareth
). The series is even better than the original, imo. I can't get it anywhere, now.
Below is the 2009 revision, rather good...
Giant Ant movie, another classic, Them! here in Spanish, in Youtube. The Spanish is from the 1950's as well, when they spoke so fast you could barely make out a word. Resolution is awful. However, you can rent the movie in Amazon, here