1. Vader taunting Luke in Cloud City - "The force is with you, young Skywalker. But you are not a Jedi yet." That line, coupled with that amazing shot of Vader, silhouetted, smoke behind him. Cinematic perfection.
2. Yoda teaches Luke - I have to cheat on this. I couldn't pick between lifting the X-Wing, and the whole speech about the force. "Luminous beings are we..." So, all of the moments between Yoda and Luke in Empire.
3. Darth Maul vs. Qui-Gon and Obi-Wan - All of this. From the moment the door opens, to Obi-Wan slicing Maul in half.
And this. Nothing needs to be said.4. Luke blows up the Death Star - From Obi-Wan's "Use the force, Luke" with the force theme swelling, to Han Solo's heroic entrance and "Yeehaw!", to Luke's bombs going down the reactor, music builds, and it all finally climaxes with an explosion. Does it get better than that?
5. Anakin vs. Obi-Wan duel - Do I need to explain? Three (or six) movies built to this moment. A few cringy moments are not enough to ruin this amazing, emotional fight to the death between a master/apprentice.
Honorable mention: I could not possibly leave out the Binary Sunset moment. It's what, 10 seconds? And yet still so iconic.