Well, I'll have to word this carefully, since I want to avoid my usual argument of "they shouldn't be viewed as one whole story!" thing. But since you posted your view of Star Wars, I simply feel compelled to post mine, that's all, and it's simply impossible to present my view without first stating that I don't believe that all six should be viewed as one single entity. Simply put, for me, Star Wars is about the war between the Rebel Alliance and the Galactic Empire. On a more character-based level, it is the journey of Luke Skywalker to make something of his life, grow, and become responsible for destroying the key players in the Empire and reviving the Jedi ideals to the universe ("Not the last of old, but the first of the new."). And when I look simply at the movies, the original trilogy, or all six, trying to wrap my mind around it being the redemption of Anakin Skywalker leaves a bad taste in my mouth. When you get right down to it, only one movie has anything at all to do with the redemption of Anakin Skywalker, and that's Return of the Jedi. None of the prequels touch on this because, at that point, he has nothing to be redeemed from. And in the original trilogy, you don't even know Darth Vader is Anakin Skywalker until the end of Empire. And no other character makes any attempts or has any aspirations to redeem him at that point, nor does he appear to want to himself. Only in Return of the Jedi does Luke come up with the notion of "redeeming" his father.

So, even if you do take all six films as one, complete story, Lucas's "It's the redemption of Anakin Skywalker" story doesn't hold water. That's like summarizing the first Star Wars movie by simply saying, "Star Wars is about blowing up the Death Star." The redemption of Anakin Skywalker is the conclusion of the story, not the story itself.