9. The Descent
Released in 2005 and almost ignored by audiences thanks to tragic timing (the movie came out in the UK mere days before a devastating underground bombing), Neil Marshall's The Descent remains an anxiety-inducing tribute to the director's horror prowess a decade and a half later.
The film is methodically paced, opening with one brutal blast of shock before taking its time setting up characters and grounding their reality for the viewer. The subterranean horror succeeds in terrifying the audience and leaving them constantly on edge thanks to a cleverly constructed screenplay that taps into every deeply resonant human fear.
Opening with the existential horror of losing loved ones, the film then moves into the much more primal and immediately impactful fear of tight, confined spaces, where it lingers throughout the unbearably slow, tense spelunking sequences.
It's only after dragging viewers from fears of emotional tragedy through to more physically resonant trauma that the film finally reveals its trump card.
The misshapen cave monsters are terrifying in themselves, but their shock appearance wouldn't be anywhere near as effective if the film hadn't gradually ratcheted up the tension and dug into the audience's bone deep anxieties. Before, you know, digging out the bones of its cast.