Hermione slapping Draco in the face. Little twerp had it coming...
And then driving Draco (who, remember, never hesitates to toss a taunt or racial slur her way) into full retreat by merely pulling out her wand. It suddenly occurred to him that he's just pushed the most talented witch in the school one inch too far.
Ron has had his leg broken by a deranged murderer (he is led to believe) and can basically be defeated by a stiff wind. So he tells that same murderer, if he wants Harry, he'll have to go through him.Steve Kloves can be safely ignored on this front: Ron is Harry's man, through and through.
Expecto Patronum! A lone 13-year-old boy against more than a hundred soul suckers.
The Quidditch Final.
The entirety of the Shrieking Shack scene.
"The Marauder's Map never lies. Peter's alive, Harry. Ron's holding him."
"I want to finally commit the murder I was imprisoned for!"
"If you want to get to Harry, you'll have to go through me!"
"THEN YOU SHOULD HAVE DIED! DIED RATHER THAN BETRAY YOUR FRIENDS, AS WE WOULD HAVE DONE FOR YOU!"
Hermione punching Draco.
Snape gets one he never got in the books. Runs out of the Whomping Willow, sees a werewolf about to eat them, and his first response is to stand between the kids and the wolf. Not bad, Snape.