7. Martyrs (2008)
Following up on the good will the French established with Inside, they follow up with another beautifully shot, extremely disturbing horror that needs your support; Martyrs. The film begins with a violent murder, though motive and cause are vague, and over the course of the film we begin to learn the who, what and why, with what begins as grim psychological thriller about two women having to clean up the remains of a murder transforming into a torture horror - though not torture porn - as one of them is taken hostage. To say much more about it than that would be criminal, given the surprises Martyrs has in store; though it might initially seem like a standard horror pic about a chained up young woman who has to escape her captors, the third act reveals something very different altogether. Delivering a twist and horror motives that are virtually unheard of in the genre, the bizarre last third is probably the most divisive element of the film, but ironically also its most successful, providing a unique and oddly sympathetic explanation for the torture and murder we have just sat through. Again, like several films on this list, you'll need a strong constitution to make it through, but it's well worth it if you're able.