For many, Anakin looked stupid with the way Episode III made him turn to the other side. For some it is quite reasonble.

For me, personally, EpIII should have put more story or background to enlightened the reason how Anakin or one could turn down his loyalty to the people he loved and join someone he just learned that's their enemy. It could be more reasonable.

or perhaps Lucas can make an exclusive video of this, or a animated story of this just like clone wars, or a novel tackling how Anakin really got confused and struggled with this. (or I just dont know, maybe there's already a book on this)