The Amityville Horror (1979) and The Changelling(1980), I kill two birds here not with one stone but pulling out its heads and sucking its little bones. Movies very representative of those years. Allright, now we can say "The typical film with a mansion possessed by strange entities" but in those years the movie was absolutely not typical. I still remember that image of ball taking the steps of stair down little by little, one by one, portent so what it's going to happen at a house where, assuming, no one's live there.
The Thing (1982), for me the best one John Carpenter's film. Perfectly acclimatized, it tell us the terror story came from the space. I find some resemblances with "Invasion of the body snatchers". Distrust your buddy, he might not be who you think