Harry smiles at an Asian girl who's not Hermione. The Shipping Wars Begin!!!
Dumbledore grabs Harry by the shoulders and pushes him against a table. I think that's rather inappropriate for a school's headmaster.
"I am not an owl!" Holy context, Batman! That quote should have been a meme.
The dragon contest is my favorite scene of the series so-far and I think it's very unlikely that will change. It reminds me of the T.rex attack from Jurassic Park or the Rancor pit from Return of the Jedi.