One of the great pleasures of the upcoming 'You're Next' is how it sets certain expectations before gleefully (and bloodily) defying them. It imagines its primary audience is familiar with how home-invasion horror movies tend to play out and takes great pleasure in offering surprise after surprise, creating one of the freshest horror movies in recent memory out of something potentially stale.

Every so often, a horror movie comes along that changes the course of the genre. Sometimes it's quiet and the ripples are gently felt for decades to come. Sometimes it arrives with a bang and filmmakers loudly chase a new trend for a few years. We're not sure where 'You're Next' will fall on the horror pantheon, but we do know that it feels like something special.

Here are 10 groundbreaking horror films that defied expectations and forever changed how audiences and filmmakers approached the genre.