Attack of the Giant Leeches (1959)
Horror sci-fi as people start disappearing in the Florida Everglades

Elephants Dream (2006)
Sci-fi animation about two people stuck in a strange world

The Last Man on Earth (1964)
Sci-fi horror, based on the novel “I Am Legend”

Plan 9 from Outer Space (1959)
Sci-fi horror directed by Ed Wood, as later featured in the Tim Burton biopic about him

Santa Claus Conquers The Martians (1964)
Notoriously awful sci-fi comedy where martians decide to kidnap Father Christmas