Type: Comedy Story: An extraterrestrial nicknamed ALF (Alien Life Form) crash-lands into the garage of a the Tanners. With ALF stranded on earth, the family decides to take him in and hide him from the military as well as from nosy neighbors.
Type: Drama Story: A slave race of aliens crash land in the Mojave Desert and are assimilated into the population of Los Angeles. These "newcomers" have to adjust to a new life and struggle for acceptance and is seen through eyes of alien policeman, George Francisco, his family and George's human partner, Matthew Sikes .
Type: Drama, Mystery, Action Story: Early in the 21st century, a race of aliens, arrive on Earth. In exchange for being allowed to take refuge on our planet, the Taelons offer the people of Earth access to their advanced technology.
Type: Thriller, Mystery, Science Fiction Story: A group of extraterrestrials are discovered to have been assimilated into the general populace since their arrival 60 years ago.
Alien(s): The various aliens who are led by Sophia Maguire
Type: Teen, Drama Story: The series follows the lives of teenage aliens, survivors of the 1947 UFO crash, hiding in plain sight as humans in Roswell, New Mexico.
Alien(s): Max & Isabel Evans, Michael Guerin, Tess Harding
Type: Science Fiction Story: Follows the exploits of a small team of alien-hunters, who make up the Cardiff, Wales branch of the fictional Torchwood Institute, which deals mainly with incidents involving extraterrestrials.
Alien(s): All the aliens that Captain Jack Harkness and his team go after including the Weevils, Nostrovites, Mayflies and the Alien Blowfish
Some more that come to mind - Threshold, Dark Skies, Earth: Final Conflict, The Tripods, Taken. What about animation: Captain Scarlet & The Mysterons? :-)
What about Roger, the alien on American Dad?