Best movies like The 27th Day

A misguided scientist enables an alien from Venus named Zontar to come to earth in order to "help solve man's problems". However, as soon as Zontar arrives on Earth, it quickly becomes obvious that the three-eyed, bat-winged, skeletal black creature has a hidden agenda.

An "unknown force" declares war against planet Earth when the United Nations disobeys warnings to cease and desist in its attempts at assembling the first satellite in the atmosphere.

A strange alien captures Porky Pig and Sylvester's entire campsite as a sample to take back to its planet, but only Sylvester figures out what is really going on.

Atomic scientist/pilot Doug Martin is missing after his plane crashes on an reconnaissance mission after a nuclear test. Miraculously appearing unhurt at the base later, he is given sodium amethol, but authorities are skeptical of his story that he was captured by aliens determined to conquer the Earth with giant monsters and insects. Martin vows to use existing technology to destroy them.

A UFO is stranded on earth and impounded by the US government. Its pilot, a cat with a collar that gives it special powers, including the ability to communicate with humans, has eluded the authorities and seeks the help of a scientist in order to reclaim and repair his ship and get back home.

After an encounter with UFOs, an electricity linesman feels undeniably drawn to an isolated area in the wilderness where something spectacular is about to happen.

12-year-old David is accidentally knocked out in the forest near his home, but when he awakens eight years have passed. His family is overjoyed to have him back, but is just as perplexed as he is that he hasn't aged. When a NASA scientist discovers a UFO nearby, David gets the chance to unravel the mystery and recover the life he lost.

Scientists and US Air Force officials fend off a blood-thirsty alien organism while investigating at a remote arctic outpost.

In California, an old man grieves the loss of his wife and on the next day he also dies. However, the space soldier Eros and her mate Tanna use an electric device to resurrect them both and the strong Inspector Clay that was murdered by the couple. Their intention is not to conquest Earth but to stop mankind from developing the powerful bomb “Solobonite” that would threaten the universe. When the population of Hollywood and Washington DC sees flying saucers on the sky, a colonel, a police lieutenant, a commercial pilot, his wife and a policeman try to stop the aliens.

In the early hours of the night, young David Maclean sees a flying saucer land and disappear into the sand dunes just beyond his house. Slowly, all of the adults, including his once loving parents, begin to act strangely.

On the same day that Tom Dunn finds out that he is to become a father again, the people of Earth become plagued with terrifying visions of the end of the world. When a gigantic, all-consuming alien mothership launches a ruthless attack, chaos and destruction follow. The ultimate war for Planet Earth is about to begin...

Eight people at a remote Scottish inn find themselves confronted by a woman from Mars, who has landed her flying saucer for repairs but intends to soon conquer the Earth and enslave its men for breeding purposes.

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

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

Test space rockets exploding at liftoff and increased reporting of UFO sightings culminate in a direct attempt by alien survivors of a dead, extra-galactic civilization to invade Earth from impervious flying saucers, using ray-weapons of mass destruction.

Mota is a Martian representative, who has come to impose interplanetary law on the Earth (which has become too dangerous); opposing his authority is Kent Fowler, who resists the alien plot, without understanding its details.

After a collision with a comet, a nearly 8km wide piece of the asteroid "Orpheus" is heading towards Earth. If it will hit it will cause a incredible catastrophe which will probably extinguish mankind. To stop the meteor NASA wants to use the illegal nuclear weapon satellite "Hercules" but discovers soon that it doesn't have enough fire power. Their only chance to save the world is to join forces with the USSR who have also launched such an illegal satellite. But will both governments agree?

A young alien falls for a pretty teenage Earth girl and they team up to try to stop the plans of his invading cohorts, who intend to use Earth as a food-breeding ground for giant lobsters from their planet.

Since the 1940's alien beings known as "GRAYS" have been sighted around the globe with the thought that they visit our planet to study our species and civilization before they eventually invade...but what if we're wrong? What if they are only here to protect us? After a meteorite crashes to earth awakening the extraterrestrial creature within, a young woman is abducted by an alien "GRAY" to aide in hunting down and destroying the creature before it can reach a second meteorite that fell to earth decades earlier unleashing its deadly infestation of earth.

Captain Rameses and his Legion of the Winged Serpent brigade are out to claim Earth for their dying race. Out to save Earth is an alien guard patrol located in the Bermuda Triangle, the League of Races. LOR leaders warn Rameses that he's breaking galactic treaty rules. The alien villain responds by launching an invasion which telepathically drives Earthlings to suicide. The LOR implore UFO expert Professor Duncan to help them. Eventually, the two alien forces battle. Will the Earth be saved?

Adrianna (Chong) is a beautiful alien woman who has come to Earth in search of a half alien man (Wirth). She needs him to help her defeat the evil alien Pallas, who himself is out to kill her.

When an atomic war on Mars destroys the planet's women, it's up to Martian Princess Marcuzan and her right-hand man Dr. Nadir to travel to earth and kidnap women for new breeding stock. Landing in Puerto Rico, they shoot down a NASA space capsule manned by an android. With his electronic brain damaged, the android terrorizes the island while the Martians raid beaches and pool parties

An alien is dispatched from a faraway galaxy to take over the Earth by "duplicating" humans and creating a race of zombies.

When the Viking space capsule suddenly returns to Earth from its long ago trip to Mars, it brings with it an intelligent visitor that is part "Alien" and part "ET". Encased in armor, it extends a human like form from its shell to examine its surroundings and shows an interest in humans including a soft caress of a female scientist prior to the Army killing it. This only enrages its sibling.

In the near future the US Government has created an elite team of soldiers specially trained for action in the event of a hostile alien encounter. A multi-national force, they are the last line of defense

A flying saucer hidden in a Red Chinese peasant village is sought by teams from the United States and U.S.S.R. On finding it, they band together to explore the saucer and take a trip into space.

An atomic explosion awakens Gammera, a giant fire breathing turtle monster from his millions of years of hibernation.

Stranger from Venus (a.k.a. Immediate Disaster and The Venusian) is the story of a woman who meets a stranger with no pulse who has the power of life and death at his touch. He is here from Venus to warn Earth about the atom.

The crew of the first manned mission to Mars crash land on the surface in search of a clean everlasting power source they believe to be hidden somewhere beneath the ground. However, the crew find themselves in the middle of a civil war between the High Priest of Mars' royal guards and the High Priestess' warriors. The crew is divided with one half deciding to help the High Priest make peace with Earth and the other side with the High Priestess who is secretly plotting to kill her husband and invade Earth.

Two eccentric aliens from outer space manipulate one man's brain so he can make telepathic love to any woman they like.

A documentary filmmaker travels to a UFO convention in New Mexico where he meets a local artist with a dark secret. As they follow a trail of clues they discover disturbing sightings and question all they believe when they become immersed in the enigmatic culture of the Pueblo Indians.

The CIA sends playboy Mike Trent to Alaska with agent Vee Langley, posing as his "nurse," to investigate flying saucer sightings. At first, installed in a hunting lodge, the two play in the wilderness. But then they sight a saucer. Investigating, our heroes clash with an inept gang of Soviet spies, also after the saucer secret.

Recovered footage and self-filmed documentary that journals a UFO sighting and possible abduction. This found footage film will test even those with the most open-minded beliefs. Is "The Rejected" actual proof of aliens on Earth or is this an elaborate hoax? We let you decide.

A beautiful grad student named Tara Simmons is abducted by aliens in a flying saucer. Four days later she finds herself back on earth at the top secret government facility Areola 51, which documents sexual encounters with aliens. She remembers everything and recounts the story of her pleasant abduction in sensuous detail to an eager but reserved government agent. Tara describes being bound and bathed by the humanoid aliens, and later being probed by their hands and instruments. She also tells of having various types of sex with the aliens and of having to train them in the ways of sensual pleasure since the alien race had lost their sexuality. As Tara continues, the agent loses interest in taking notes, and becomes aroused and eager to hear more. She also reports that the aliens made her own sexual fantasies seem real as a way to study sex and to reward her. Finally, Tara seduces the agent, but may have an ulterior motive.

When an overconfident teen alien gets behind the controls of a spaceship, he must attempt to abduct a slumbering farmer under the watchful eye of a critical instructor. But abducting humans requires precision and a gentle touch, and within a few missteps it's painfully clear why more humans don't go missing every year.