Well, after seeing Revenge of the Sith last night @ the midnight showing, I've had a few hours to contemplate the sound design of the film.
The single greatest sound in the film which soaked up applause, (a first time for a sound effect to my knowledge) was the very first breath of Vader after he's been sealed in his isolation. We see the mask lower onto Anakins head. The mask seals shut. The theatre is silent enough to hear your own heart beating. Everyone holds there own breath...waiting to hear the sound that has defined an icon for generations. And...the first breath is taken by the computer that controls Anakin's respiration functions. Thunderous roar takes the crowd in the theatre. At the screening I was at, this was the single greatest moment that garnered the loudest applause during the movie. The sound effect was enough to give me goosebumps (which is always the telltale sense that a sound is legendary.)
Overall, the sound of the film is without comparison the finest mix of the entire Star Wars Saga. In upcoming blog entries, I'll be picking apart the soundtrack that had me blown away. I'm really interested to hear what were some of your favorite sounds in the film. Let me know.