Winston is heroic in daring to oppose the state. As Nafasi writes in Reading Lolita in Teheran, in a totalitarian state, the smallest of gestures, such as a woman allowing a few strands of hair to fall out from her veil, becomes an act of rebellion.
Winston's rebellion runs deep. He writes in a diary, although he knows it will lead either to his death or twenty five years at a hard labor camp. He has a forbidden affair with Julia and even rents a room above Mr. Charrington's shop so that the two can, every so often, live like an ordinary couple. He states to O'Brien that he is willing to take great risks to help overthrow the current government.
After his arrest, Winston is heroic in resisting the idea that two plus two equal five, even while being tortured, and he tries to hang on to his love for Julia as long as possible. If he cannot "win," he at least fights a good fight.