10 Movies You Should Never Watch Alone

Another film that falls in the 'watch once but never again' category is French writer-director Gaspar Noé's unflinchingly brutal 2002 tale of revenge on the streets of Paris, which relays its events in reverse chronological order.

After an unforgettably savage act of vengeance early on, things only get more unpleasant the further back we go, as Vincent Cassel's Marcus and Albert Dupontel's Pierre seek bloody retribution for the brutal rape of Marcus's girlfriend Alex, played by Monica Bellucci.

Noé has long had a much-deserved reputation for his shocking, confrontational visions which do not spare the audience, and Irreversible is arguably his crowning achievement in this respect, thanks not only to the horrific opening, but even more so to the unforgettably harrowing rape sequence, in which the camera never moves or cuts away for the entire 10 minutes of Alex's appalling ordeal.

While Irreversible can be classed as a key film in both the French Extremity wave of the 2000s, as well as an influence on the American 'torture porn' trend, it's an altogether different breed of extreme cinema, blurring the lines between art and exploitation to enormously uncomfortable effect.

Very few viewers are likely to profess that they actually enjoyed seeing Irreversible, but many have applauded its artistry, and surely no viewers will be left unmoved at all. Even so, it's doubtful anyone would want to sit through it a second time.