Earth vs. the Flying Saucers (1956)

Ba'al travels back in time and prevents the Stargate program from being started. SG-1 must somehow restore history.

During the reign of the Vikings, a man from another world crash-lands on Earth, bringing with him an alien predator. The man must fuse his advanced technology with the weaponry of the vikings to fight the monster.

An alien and a robot land on Earth after World War II and tell mankind to be peaceful or face destruction.

Strange phenomena surface around the globe. The skies ignite. Terror races through the world's major cities. As these extraordinary events unfold, it becomes increasingly clear that a force of incredible magnitude has arrived. Its mission: total annihilation over the Fourth of July weekend. The last hope to stop the destruction is an unlikely group of people united by fate and unimaginable circumstances.

A fleet of Martian spacecraft surrounds the world's major cities and all of humanity waits to see if the extraterrestrial visitors have, as they claim, "come in peace." U.S. President James Dale receives assurance from science professor Donald Kessler that the Martians' mission is a friendly one. But when a peaceful exchange ends in the total annihilation of the U.S. Congress, military men call for a full-scale nuclear retaliation.

Susan Ivanova discovers a derelict spaceship in hyperspace. They tow it back to Babylon 5, then strange things start happening. People are being telepathically taken over by aliens from another (third)space.

16-year-old Cassie Sullivan tries to survive in a world devastated by the waves of an alien invasion that has already decimated the population and knocked mankind back to the Stone Age.

A civilian oil rig crew is recruited to conduct a search and rescue effort when a nuclear submarine mysteriously sinks. One diver soon finds himself on a spectacular odyssey 25,000 feet below the ocean's surface where he confronts a mysterious force that has the power to change the world or destroy it.

Aliens have landed and are hiding on Earth, but need Earth’s scientists to help them fight an inter-planetary war.

When an alien race and factions within Starfleet attempt to take over a planet that has "regenerative" properties, it falls upon Captain Picard and the crew of the Enterprise to defend the planet's people as well as the very ideals upon which the Federation itself was founded.