The most memorable moment for me was when Winston told O'Brien that the resistance will win because they are basically the"good guys" (don't remember the exact dialogue) and O'Brien plays a tape of Winston saying he would throw acid into the face of a child without question if it helped the resistance.

I don't know any author who is able to create such utter hopelessness like Orwell. Being in constant pain while writing 1984 must have helped.