I find it fascinating that, after seeing Episode III, a lot of scenes from the previous movies have now acquired a new meaning. Not only scenes from Episodes IV, V, and VI, but also from I and II. I am sure that there are a lot more of these, each one a debate or discussion on its own, but these are my favorite ones:
"Your father's lightsaber." When Obi-Wan passed on Anakin's lightsaber to his son, he decided that it was best for Luke to remember his father as a hero of the Clone Wars, a great pilot, and a great Jedi Knight of the Republic. But if Luke only knew how much blood was tainted on that weapon. Sure, it was the same lightsaber Anakin used during the Clone Wars, but I can't help to think that it was also the same weapon he used to cut Mace Windu, kill the Jedi at the Temple and the Separatist leaders, and fight with Obi-Wan to the death. Luke held on to his father's lightsaber with pride, and he never knew.
"There is still good in him." Now it becomes clear that the climax of the whole Star Wars saga is not Luke Skywalker becoming a Jedi, but saving Anakin Skywalker's soul. Obi-Wan was right when he said that Darth Vader had killed Anakin. That is why Yoda and Obi-Wan did not believe he could be turned. But first Padmé and then Luke believed that the "good man" who was Anakin could come back. And it now makes perfect sense to see a young Anakin coming back from the afterlife at the end of Episode VI.
"There is a great disturbance in the force." I have really enjoyed the recent analyses some fans have given about the Emperor's hologram message from Episode V. And I agree with the consensus. Palpatine lied to Darth Vader, and for twenty years he believed that Padmé had died before she gave birth. But shortly after the Death Star was destroyed, he learned about Luke Skywalker and became obsessed with finding him. When the Emperor contacted him during his search, he wasn't informing him that Luke was his son, he already knew that. He was basically saying, "I know that you know."
"She was very beautiful. Kind, but... sad." I don't know why this scene confuses some people. I think it actually makes more sense now. Leia remembers Padmé at the time of her death: A beautiful woman that died of a broken heart.
"What a desolate place this is." Sure, we all knew that a memory wipe would explain C-3PO not recognizing his home planet of Tatooine and that it would save him years of therapy from knowing that Darth Vader was his maker. But, how many of us knew that R2-D2 did not get a memory wipe, and that he knows about everything that has happened, and that he is just keeping quiet?
"The Jedi Master who instructed me." Some people just couldn't stop complaining about this line. "Why does Obi-Wan say that Yoda trained him, when in fact Qui-Gon was his Master?" Well, it is implied that Yoda trained Obi-Wan when he was a Youngling, before becoming Qui-Gon's Padawan. But, as we can tell from the end of Episode III, Yoda trained Obi-Wan even as an adult when he was already a Master. Yoda taught him how to comeback from the afterlife and instructed him to train during his years in Tatooine. So, the way I see it, Yoda trained Obi-Wan during different stages of his life.
"Join me." I now understand how cancerous the Sith Master/Apprentice relationship is. We saw a little bit of that between Darth Tyrannus and Darth Sidious. Darth Vader wanted to overthrow the Emperor and rule the galaxy along with his wife. When that did not happen, he wanted his son to join him and destroy the Emperor. But Palpatine wanted to get rid of Vader and have Luke take his place. So, one wanted to kill the other, and at the end they destroyed each other.
"The Emperor's coming here?" Palpatine is my second favorite character in the whole Star Wars saga. Who knows how long he planned his revenge on the Jedi, but once he sets his plan in motion, its amazing to see how this character is unraveled. His death at the end of Episode VI is made all the more significant because now we know all the evil that he represents.
"Do not...Do not underestimate the powers of the Emperor, or suffer your father's fate, you will." We already knew that Yoda was warning Luke about Palpatine's powers of seduction to the Dark Side, but now we know that his warning also implies the Emperor's Force lightning and lightsaber skills that he experienced first hand. I think that Yoda and Palpatine are the characters that most benefited from the prequels. It is clear that Palpatine is Yoda's antithesis and that one is just as powerful as the other one is. It is no coincidence that they appear in the same number of episodes.
"He has too much of his father in him. / That's what I'm afraid of." How much did Owen Lars knew about his stepbrother Anakin Skywalker? Maybe he learned about the Tusker Rider Massacre after Anakin left Tatooine. He sure didn't miss C-3PO, but he did wish for a simpler life for Anakin.
"...On your home planet of Alderaan." Whether I want to or not, I can now visualize the destruction of this peaceful planet from Bail Organa's point of view.
"He's no good to me dead." The connection between the Stormtroopers and Boba Fett is just perfect. Who knew Jango Fett's face would be under those helmets.
"I'm getting too old for this sort of thing." Yeah, now we know who the Jedi were and what they could do. By "this sort of thing," Obi Wan means evading clone troopers, skydiving through buildings and air traffic, facing bounty hunters and cyborg generals, and chopping up Sith Lords. But one is never too old for a good mind trick.