3. Aron Ralston's Arm (127 Hours)
127 Hours Tells the true story of Aron Ralston; a climber and all round adventure-seeker who was spending some time in Utah's Canyonlands National Park. After parting company with two girls he met, he ventures alone in to Blue John Canyon - a narrow passage where boulders are suspended, wedged between the walls of rock. As he heads down in to the canyon, one of the boulders comes loose and he falls to the bottom - quickly followed by the boulder, which rather inconveniently wedges his arm between it and the canyon wall. After spending over five days trapped, in which he becomes starved, dehydrated and begins to hallucinate, knowing he is faced with certain death, Ralston has no other choice but to amputate his own arm in a desperate attempt to free himself. His first attempts fail, but using the sheer force of will to live, he manages to break his own arm and cut it off with a knife. It's a truly agonising, brutal five minute scene which shows the knife explicitly carving through skin, muscle and bone. Not for the squeamish - and it's even harder to watch knowing that it really happened.