Day 22 and 23. When all the TIE Fighters are flying past the rebel fighters at the opening of the second death star battle. And I wish they kept Darth Vader's ghost and not added young Anakin in the end.
The seismic charge detonations. I still use that to test my sound system any time I move house or set up someone else's stereo. It has the initial clean sound (test the clarity of the speakers) then the destruction through the asteroids (tests the eveness of the surround sound setup). Takes 15 seconds and confirms so much
Day 14. The brief moment they show when the rebels are setting up and quietly waiting for the Imperial walkers to arrive in the battle of Hoth. John Williams has some eerie music playing and it sets everything up!