A while back I was reflecting on Star Wars, and in particular the transformation of Anakin Skywalker into Darth Vader. It occurred to me that Vader is the "bad guy", so Anakin becomes Vader despite the audience's wishes—but wouldn't it be great if the audience watched a descent into evil and actually rooted for it the whole time? That would be an achievement indeed. Then I realized that this movie has already been made: it's called The Godfather, with Michael Corleone in the Anakin role. In Part II, we watch Vito Corleone go through the same transformation, and watch Michael descend even further. And, amazingly, we never stop liking them.
*Reload your browser for proof. :-)
*I love all the Star Wars movies—yes, even the prequels.† It's hard for me to imagine a world without Luke, Leia, Han, Chewbacca, R2-D2, C-3PO, Obi-Wan Kenobi, Yoda, and Anakin/Vader. As a youth, George Lucas was nearly killed in a car crash so bad it made the local newspaper. I find myself retroactively grateful that he survived—my life is much richer for it.
†I know that Jar Jar is annoying and midi-chlorians are lame. Try watching the prequels again now that you know that Senator Palpatine becomes the Emperor. You'll see that they are a case study on the dynamics (and devolution) of democratic political systems. Maybe you don't think that's as cool as the hero's journey of the original trilogy, but I find it endlessly fascinating. Plus, there are more lightsaber duels—lots and lots of lightsaber duels. :-)