What's it about? Best friends Marie (Cécile De France) and Alex (Maïwenn Le Besco) head out to the countryside to visit Alex's parents but find themselves attacked by a psychotic delivery man. As the carnage escalates the two women struggle to fight for their lives - but one of them harbours a dark, deadly secret of her own.What makes it groundbreaking? More than a few people were miffed to say the least by the twist ending, which is borderline ridiculous and renders much of what came before incomprehensible, and High Tension is a far cry from being the best horror movie on this list. But it deserves a mention for kick starting the horror wing of the New French Extremity movement and in this sense can be seen as the trigger for a new era of horror since 2000, leading to such greats as Martyrs and Frontiere(s).Do you agree with the selection of groundbreaking horror movies on this list? Is there anything significant you think we've missed out? Why not post a comment and let us know?