OUT OF THIS WORLD
Short Version: That show you vaguely remember about the alien girl who could freeze time. Long Version: Evie Garland, the main character, is half-alien, which gives her a variety of special powers, which get her in and out of trouble on this syndicated half-hour Sitcom which ran from 1987 to 1991. She lives with her human mother, Donna Garland, and only communicates with her Anterian alien father Troy via a crystal on her desk (voiced by Burt Reynolds).
ALF
The brainchild of puppeteer/producer Paul Fusco and veteran television writer Tom Patchett, ALF is the story of Gordon Shumway, a hapless Alien Life Form who crash lands in the backyard of the Tanner family (no, not them) after his home planet, Melmac, explodes. The original series lasted from September, 1986 to March, 1990 on NBC, with a total of 102 episodes in four seasons, plus a movie released on February 17, 1996, to wrap up the series.
MY FAVORITE MARTIAN
An American Fantastic Comedy series that aired for three seasons (1963–66) on CBS. "Uncle Martin" is a Martian anthropologist who crash lands on Earth. Martin becomes the house-guest and adoptive "uncle" of reporter Tim O'Hara while he fixes his spaceship. Martin is extremely intelligent and has an array of powers including mind-reading and invisibility. He's also 450 "Martian" years old, and knows more about Earth and its history than most Earthlings, having visited many times before.
3rd ROCK FROM THE SUN
A '90s Sitcom in which a team of aliens come to Earth disguised as a human family in order to study mankind. The Solomons are a team of aliens who are sent to pose as a human family so they can learn about Earth and study humankind. It's mentioned throughout the series that they've done the "pose as local life-forms" mission on other planets before and that Earth is often more challenging and confusing than they were expecting.
MORK & MINDY
This 1978–82 Fantastic Comedy series on ABC, created by Garry Marshall and spun off from an episode of Happy Days, introduced the world to the comic genius of Robin Williams.
Williams played Mork, a visitor from the planet Ork sent to Earth to study and report on human behavior. After his egg-like space vessel landed near Boulder, Colorado, Mork moved in with the first human he encountered — a pretty young woman named Mindy McConnell (Pam Dawber) — and used her home as a base from which to observe humans and their strange ways.