Once I would have said Empire Strikes back. Now I'm probably leaning more towards District 9.
Someone already mentioned it, but I definitely love Logan's Run.
The Lost World: Jurassic Park
Jurassic Park III
Star Wars: Episode I – The Phantom Menace
Star Wars: Episode II – Attack of the Clones
Star Wars: Episode III – Revenge of the Sith
Star Wars: The Force Awakens
The Alien Trilogy, do not watch Alien 4.
Either Back To The Future Trilogy or the Star Wars movies
Man of steel
Seen most of the fan favorite films from the 70's into the present. I would say most liked by society in general would have to be the Original Star Wars followed closely by Star Trek The Motion Picture and Alien. Of course you also have to mention The Terminator.