This Side of Paradise springs to mind as well. For me, it was when Spock said, "I love you... I can love you." It was such a great feeling to see him embrace that side of himself fully for the first time. Reminds me of when I first said that to a girl.
I also gotta admit it was a bit emotional when Spock finally lashed out in anger when his best friend, Kirk, was taunting him with insults he had to endure as a child, only this time he was an adult that could fight back instead of just cry over it with a mother desperate to embrace him, while his father fobid it. Damn you Abrams for not understanding that when you tried to do the same thing in your film!