A Clockwork Orange
This is Alex's story, as told through Alex's eyes, so naturally he is the protagonist. Some say that Alex doesn't exactly encompass traditional protagonist qualities, such as being a non-evil person. We forgive him, though, as he comes to terms with actually growing up at the end. Others argue that Alex is a hero who doesn't just lie down and take it from the State – quite the opposite, he fights against what he believes is cruel and inhumane treatment. You just have to decide for yourself whether he's more evil or heroic, or whether he is in fact the ultimate anti-hero, which would be a combination of both.