Green Room (2015) 
Whilst not straight-up horror, this is certainly a terrifying piece of film-making as it details the exploits of young punk band trapped in the venue they’ve performed in after they are witnesses to a murder.
From that moment on the adrenaline factor is ramped up as it becomes apparent that this seedy, grotty little pit is actually a front for a white supremacist skinhead movement headed by none other than the inimitable Patrick Stewart.
Playing out over one night, Saulnier’s Green Room is a gritty unflinching cacophony of hellish terror that has been purposefully and methodically brought down upon the group of hapless teens, in turn flipping their world’s upside-down in mere minutes. The pace is rapid, where it doesn’t dwell nor linger, instead briskly hurrying itself along as if to mirror the group’s sense of panic and urgency to escape the metal and mortar coffin they have been entombed inside.
The cast as a whole are strong and performances are credible, which in turn drives the story forward. Nothing seems forced and out of place and instead you’re sucked into this nightmarish world and share the band’s plight as it unfolds – you actually care for the characters and their ordeal unlike so many films of this ilk. The film is also beautifully shot and edited to the extent where you can almost smell the dive-bar sweat and blood in the air and this adds to the overall aesthetic very nicely.
Future re-watches will hopefully fully cement the theory that this one is indeed a modern day masterpiece.