Easily top 3 across all 8 films.
Everything before is just glimpses you get from mundane day to day school, work, and play.
Then we get this. The villain so scary that no one says his name versus the one guy that villain is scared of, and they pull off stuff we never see before or after. We get an idea of just how good these two really are when they let loose.
The films mishandled some things and left out even more as the series went on, like making every bad guy a flier instead of just Voldemort or some of the rooms in the Ministry that were in the books, but this scene (and the one before, minus the flying) were brilliant.