These films would for the most part be considered B-films but B-films can still be classics within the genre, n'est pas?!
Them directed by Gordon Douglas:
Ants that have been mutated due to radiation have now become a problem for the city of Los Angeles. With them being 12 feet long and able to lift tons you could see how they could be a problem.
The Beast From 20,000 Fathoms directed by Eugene Laurie:
After an A-bomb is tested in the Arctic it awakens a prehistoric dinosaur. The dinosaur then heads to New York City causing all kinds of trouble.
World Without End directed by Edward Bernds:
Entering accidentally into a time warp, some astronauts on a mission to Mars enter into a post-apocalyptic future Earth. There is a diminishing amount of survivors living underground who have to deal with mutant creatures.
Satellite in the Sky directed by Paul Dickson:
A crew along with a stowaway female reporter direct a jet rocket ship on its first space flight. They will also undertake the first outer-space detonation of a tritonium bomb. A mechanical failure, however, will put everyone at risk.
Special Features: Behind-the-Scenes Archive Footage Showing How Giant Ants Operate, Bug Movies Production Notes, Theatrical Trailers, The Rheodosaurus and the Roller Coater: Making the Beast, Harry Hausen and Bradbury: An Unfathomable Friendship, Giant Monsters Trailer Gallery