Friday The 13th (1980)

When a summer camp at idyllic Crystal Lake reopens 25 years after the tragic drowning of a young boy named Jason, the woods fill with the happy squeals of young campers and the sight of the furtive couplings of libidinous counselors. But when a violent rainstorm isolates the lake, one-by-one the counselors are horribly murdered in this film that launched a modern horror genre.