Above Image: V Diana (Jane Badler), Star Trek Spock (Leonard Nimoy), Doctor Who (Matt Smith)
25. Klaatu from "The Day the Earth Stood Still"
Klaatu is the alien from the 1951 science fiction film The Day the Earth Stood Still and, to lesser extent, its 2008 remake. The first film, played by Michael Rennie, is the most iconic. With a flying saucer and his giant robot, Gort, he's a peaceful ambassador from an extraterrestrial confederation and gets shot several times trying to bring peace. But, he keeps on trying, and sends a message that peace is worth fighting for. "Klaatu barada nikto!"
The star of the 1978 Disney film Cat from Outer Space is another flying saucer jockey. When his ship crash-lands on Earth, the government takes the ship and it's special collar. Turns out Zunar-J-5/9 Doric-4-7 looks exactly like your average house cat and is adopted by Dr. Franklin 'Frank' Wilson (Ken Berry) and Dr. Elizabeth 'Liz' Bartlett (Sandy Duncan). Madcap adventures follow in your typical 70s Disney movie, but in the end, the Cat from Outer Space saves the day. Depending on your view of cats, this is either the exactly what real cats would do or proof he's an alien.
22. Engineer from “Prometheus”
First seen in the Derelict ship in Allen and nicknamed "Space Jockeys," The Engineers (also called Pilots,Ossians or Mala'kak) are the most highly advanced ancient extraterrestrial race in the galaxy. These masters of genetic engineering are bald, seven foot tall and muscular with black eyes. While benevolent, the Engineer encountered by the crew of the USCSS Nostromo was tempermental and angry.
21. Dathon from "Star Trek: The Next Generation"
The Star Trek: The Next Generation episode "Darmok" featured a truly unique alien race called the Tamarian. When the starship Enterprise is sent to make contact with them, they are both frustrated with their inability to communicate. While the universal translators work fine, it sounds like a bizarre string of non-sensical phrases. The Captains of both ships, Dathon (Paul Winfield) and Picard (Patrick Stewart) are suddenly transported to the surface of a nearby planet and the ship's transporters are rendered useless. Fear sets in. But, over time, the answer is revealed and Dathon gave his life to bring peace and understanding. Dathon showed that true understanding comes from recognizing our differences. The episode was also the acting debut actress Ashley Judd, as Ensign Robin Lefler.
20. Apophis from “Stargate: SG-1”
"Someone's got to teach that guy how to die!" Jack O'Neill once said. On the television show Stargate SG-1 Apophis (Peter Williams) is a Goa'uld System Lord and the main villain. After his brother, Ra, is killed by Daniel Jackson and Jack O'Neill he takes control. His attacks on Earth restarts the Stargate Program. Arrogant, egotistical and a powerful fighter he enjoyed torturing his enemies. Apophis knew his limitations though and was willing to seek help with his long-range plans. He died saying the name of his wife.
19. Aliens of "2001: A Space Odyssey"
The 1968 science fiction film 2001: A Space Odyssey, produced and directed by Stanley Kubrick, featured a mysterious alien race that has guided human progress for thousands of years. While they were never shown in the film, Kubrick described them as having progressed from biological beings to "immortal machine entities" and into "beings of pure energy and spirit".
18. T'Pol from "Star Trek: Enterprise"
Commander T'Pol (Jolene Blalock) is a Vulcan who serves as the science officer aboard the Star Trek: Enterprise starship Enterprise. Beautiful, and more emotional than other Vulcans, T'Pol helped to build relations between humans and Vulcans
17. Mathesar from "Galaxy Quest"
Mathesar is the leader of the alien race known as Thermians. While Thermians are octopoids, they have the ability to appear as a white-skinned, gray-clad, black-haired humans. Actor Enrico Colantoni is credited with the awkward movements and bizarre voice. In their humanoid form they smile constantly, even when sad or scared. Mathesar shows an incredible loyalty to his people and the crew of the Galaxy Quest. In the end, he showed himself courageous, and became a hero to his own people.
16. Stitch from "Lilo and Stitch"
Lilo & Stitch is a 2002 animated movie about a little girl who befriends Experiment 626 after he lands on Hawaiian Island of Kauai. She names him Stitch and treats him like a dog, but soon he becomes a dear friend.
15. Mork from "Mork and Mindy"
Mork first appeared in the Happy Days episode, "My Favorite Orkan". He was played by, then-unknown, comedian Robin Williams. The spin-off series "Mork and Mindy" had Mork coming to Earth to observe humans and befriending 21-year old Mindy (Pam Dawber). His misunderstanding of human culture made him both hilarious and endearing.
14. Pizza the Hutt from "Spaceballs"
A parody of Star Wars' Jabba the Hutt, Pizza the Hutt (voice of Dom DeLuise) looked like a giant slice of pizza, but he had the attitude of the Godfather. Captain Lone Starr owed him a debt and Pizza made sure he wouldn't forget it. Pizza died when he was locked in his limo and ate himself. This is proof of the humor, or lack of it, depending on your view of the film.
13. Marty the Martian from "Looney Tunes"
12. Isabel from “Roswell”
11. Aliens of "War of the Worlds"
Based on the science fiction novel War of the Worlds in 1898 by H. G. Wells, several movies have told the story of a Martian invasion of Earth. The most recognizable one is the 1953 film starring Gene Barry. The image of the floating ships with their eye stalk and three fingered hands are still terrifying. As is their ridiculous lack of preparation for Earth disease. It won an Oscar for its special effects and was later added to the Library of Congress' National Film Registry.
10. The Mutant from "This Island Earth"
In 1955 the movie This Island Earth, directed by Joseph M. Newman, featured the bulbous-headed Mutants. Enslaved by the people of Metaluna as workers they ended up attacking their masters. While the movie is famously lampooned by the Mystery Science Theater 3000 movie, at the time, it had ground-breaking special-effects.
9. Buck from “Alien Nation: The Series”
The teenage son of George Fransisco, Buck Francisco (Sean Six) is one of hundreds of alien "Newcomers" living in Los Angeles in the 80s show Alien Nation. While he is the son of a proud policeman, his frequent fights for the rights of Newcomers sometimes put him at odds with the law. At first, he hated humans, but eventually comes to love them like his father.
8. Diana from "V"
7. Q from "Star Trek: The Next Generation"
Captain Jean-Luc Picard described him best when he said, "He's devious and amoral and unreliable and irresponsible and... and definitely not to be trusted." Technically, Q is the name of an entire race of aliens. But the best known one is played by John de Lancie. He is supposedly omnipotent and has vague motivations. First seen in the pilot episode of Star Trek: The Next Generation, Q returned again and again because of his hilarious dramatic chemistry with Captain Jean-Luc Picard.
6. Martian Manhunter
The Martian Manhunter (J'onn J'onzz) is a member of The Justice League and a DC comics superhero. First appearing in Detective Comics #225 (Nov. 1955). The last surviving Martian, he has green skin and can change his shape. A tragically quiet figure, Martian Manhunter is a true outsider and beloved by comic fans everywhere.
5. E.T. from “E.T: The Extra-Terrestrial”