Rocky Horror

1951 US science fiction horror film directed by Robert Wise

Disaster seems imminent when scientists discover that the planet Mongo is about to crash into Earth. Luckily, heroic young Flash Gordon is on hand to lead an investigative mission into outer space and onto the speedily approaching planet. There, he and his best girl, Dale, who is along for the ride, learn that Ming, the devious ruler of Mongo, has purposely put the planet on a collision course with Earth, and only Flash can stop him.

Working in Dr. Cranley's laboratory, scientist Jack Griffin was always given the latitude to conduct some of his own experiments. His sudden departure, however, has Cranley's daughter Flora worried about him. Griffin has taken a room at the nearby Lion's Head Inn, hoping to reverse an experiment he conducted on himself that made him invisible. But the experimental drug has also warped his mind, making him aggressive and dangerous. He's prepared to do whatever it takes to restore his appearance.

Adventurous filmmaker Carl Denham sets out to produce a motion picture unlike anything the world has seen before. Alongside his leading lady Ann Darrow and his first mate Jack Driscoll, they arrive on an island and discover a legendary creature said to be neither beast nor man. Denham captures the monster to be displayed on Broadway as King Kong, the eighth wonder of the world.

IT CAME FROM OUTER SPACE is unquestionably on my top 3 from the many sci-fi movies made in the 1950s. I review many sci-fi films from the 50s, both B-movies AND classic. THIS film would definitely go down as one of the all-time classics. Even more rich with every viewing, IT CAME FROM OUTER SPACE is about a couple who live in a desert, one a scientist. One night, the scientist and his girlfriend are stargazing when they see some strange thing crash into a crater. When they go there, the scientist decides to go down, and sees a strange ship right before an avalanche falls over the specimen. Soon those two are the only ones who believe it is a ship from outer space, until strange things begin happening. The scientist must solve the mystery of why the aliens have arrived, and what they want. A science fiction classic worth buying on DVD. (Don't be fooled...the alien looks nothing like the one on the DVD cover.)

Doctor X (1932) is a First National/Warner Bros. horror and mystery film. Based on the play originally titled The Terror (New York, February 9, 1931) by Howard W. Comstock and Allen C. Miller,[1] it was directed by Michael Curtiz and stars Lee Tracy, Fay Wray, and Lionel Atwill.
The film was produced before the Motion Picture Production Code was enforced. Themes such as murder, rape, cannibalism and prostitution are interwoven into the story. The film was one of the last films made, along with Warners' Mystery of the Wax Museum (1933), in the two-color Technicolor process. Black and white prints were shipped to small towns and to foreign markets, while color prints were reserved for major cities.
PS. The Return of Doctor X (1939) link:

Starship C57D travels to planet Altair 4 in search of the crew of spaceship "Bellerophon," a scientific expedition that has been missing for 20 years, only to find themselves unwelcome by the expedition's lone survivor and warned of destruction by an invisible force if they don't turn back immediately.

1955 science fiction film directed by Jack Arnold

After an unusual meteor shower leaves most of the human population blind, a merchant navy officer must find a way to conquer tall, aggressive plants which are feeding on people and animals.

American psychologist John Holden arrives in London to participate in a symposium aiming to expose witchcraft and devil-worship as a fraud, with attention centered on a cult run by a Julian Karswell. Debarking his plane, Holden learns that the symposium leader, Henry Harrington, has suddenly died and he is now in charge. What only the audience knows is that Harrington was clearly killed by a demon, apparently summoned by Karswell to avenge his persecution. Despite both threatening and cajoling behavior by Karswell, Holden determines to proceed, though the only cult member willing to talk about his experiences is in a prison psychiatric ward, catatonic after allegedly killing yet another cult member. However, Harrington's niece, Joanna, believes, based on her uncle's notes, that Karswell may indeed have some satanic powers derived from an ancient tome in an obscure language which he has been able to translate, and attempts to warn the skeptic Holden. Karswell's mother also attempts to warn Holden off. However, the thing which begins to most get to Holden are the occasional, but mounting, sensory and mental disturbances he begins experiencing after an encounter with Karswell, and the discovery that, during this encounter, Karswell secretly slipped a slip of parchment with a curse in runic symbols on it into Holden's belongings, a parchment identical to one Harrington recorded having had passed to him in a similar manner shortly before his death... [N.B. Holden at no point stays at the Karswell estate].

1951 film by Rudolph Maté