I personally think the casting for an actor to play Anakin has been a poor choice, not once, not twice, but thrice.
Jake Lloyd was way too cute and adorable to convey a child that might be conflicted between light and dark.
Hayden Christensen was... well he was hamstrung by poor dialogue and acting inexperience but he was horribly wooden and didn't have the watchable charisma to lead such a big movie.
And Sebastian Shaw looked like some kindly old grandfather from Downton Abbey, when he should have looked like an imposing, craggy military man.
I believe Dave Prowse was wrongly identified as 'leaking' info to the newspapers, and as a result they kept him of set as much as possible for Return Of The Jedi. He also had a thick West Country accent. Personally I think Dave Prowse with the make up and dubbed by James Earl Jones would have been a better option than Sebastian Shaw.