the redemption scene for ROTJ comes second for me, though I do love the whole part, from vader goading Luke about his sister, to the "you've failed your highness" line, and finally to the lightning/death of the emperor bit. But my favourit scene is yoda lifting the x-wing out the water. When Luke tries and Yoda seems to believe for a second he can do it, followed by the disappointment. Luke is just annoyed in general at Yoda asking for the ridiculous, then having to watch as Yoda manages to do it. "That is why you fail." The resignation in Yoda's voice when he says that, as if he's starting to fear that Luke won't be able to fulfill his destiny, I just love it all!