I voted Lawful Evil. In my view, Vader genuinely believes that he is bringing a perfect order to the galaxy ever so slowly. However, I can see why one might say he has traits of Lawful Neutral AND Lawful Evil. Also, he can be quite dispassionate. People say that Vader is defined by rage, but I think he's actually quite cold and analytical. He knows how to control his anger as a true Sith Lord would. Having said all that, I'm biased by the Classic Trilogy and OG EU versions of Vader. I think the Disney EU Vader is a bit more like Prequel Anakin Skywalker. CT Vader is, as well, but not nearly to the extent of the Disney comics.