I will give you two:
The first is Winston's first encounter with Julia where they meet and go off into the country in order to have sex. He finds it to be exhilirating physically but also because he feels it is an actual act of defiance against big brother, that in their coupling they are working together to bring down the Party in a way.
The second is the discovery of the journal. Though it is referred to only as something that happened prior to our entry into the narrative, it is obviously one of the most important things that happened to Winston and he sees it as the place where he actually starts being able to analyze his motives and think about his place in the world more than he did prior to its discovery.
At the beginning Winston is a man desperate to feel something, anything. The iron grip of the totalitarian party has sucked the life out of Winston. He spends any "free" time he has by sucking back vile Victory Gin to forget about is monotonous inconsequential life. In desperation, Winston buys a contraband diary in a futile effort to feel and record something.
1. Winston buys diary. He does not know what to write or to whom. He does feel an "awakening" of sorts.
2. Winston sees Julia and is deathly afraid of her. He thinks she is most certainly part of the thought police.
3. Winston gets note from Julia. It says "I Love you". Winston feels many intense emotions for the first time.
4. Winston meets Julia and they have "hot loving". Winston feels young again but living on borrowed time.
5. Winston and Julia meet with O'Brien thinking they can be part of some brotherhood to revolution. This is what Winston has dreamed of but never thought possible.
6. Winston was right, it was not possible. Winston and Julia are caught. O'Brien tortures Winston for about four chapters. Winston feels his brain getting fried and all the terror of room 101.
At the end Winston is not really Winston anymore. He swills back Victory Gin and plays chess with imaginary opponents at the Chestnut Tree Cafe. He drools allot and thinks he loves Big Brother.