One of my earliest memories of the 80s is going to my cousin's house and watching An American Werewolf In London. I was about four years old and this movie scared the hell out of me. I still won't watch it at night.
Two American teenagers are backpacking across Europe when one is attacked by a wolf and bitten. The other is killed by the wolf. The one that escaped with only a bite turns into a werewolf, as it was not just a wolf but a werewolf that attacked them. The new werewolf terrorizes London for some time until he is finally killed with a silver bullet. Through the movie the survivor is haunted by the decomposing corpses of those he kills and that of his friend.
Though it was released in 1981, Rick Baker's makeup was phenomenal. The graphic special effects were top notch by the standards set in 1981. The film won an Academy Award for good reason.