I'd have to put the RotJ duel between Luke and Vader as the most visceral. The way it was filmed & edited was really quite fantastic, and the dramatic build-up to the fight was on-the-money. Music, camera movement, choreography, effects, drama, performances, shot composition ... all of it came together quite nicely.
Which leads me seemlessly into the biggest opening night crowd reaction in the entire series (in case you were wondering from my post above) .... the moments where Vader is deciding whether to kill his son or his master ... well, even though everyone knew what the outcome was going to be, you've simply never heard anything like a theater of 1500 people all screaming at the top of their lungs. It was wonderfully intense.
(And kinda reminds me of the destruction of the Death Star in Star Wars ... in that everyone knows it's going to happen from the very opening crawl of the film, yet audiences erupt in honest cheering due to the excitement generated by that moment in the movie. That this happened time and again in theaters .... in Nineteen Freaking Ninety Seven when the film was already 20 years old ... is a testament to the greatness of the original Star Wars, imho.)