Contrast that with Hayden Christensen--who had two films as the character making the pivotal journey, but he was awful in every frame, without any sort of growth in either movie.
I agree Christensen was far worse than Hammill but for the purpose of this thread I thought we were only evaluating New Hope actors - the oriignal group.
The OP listed some obscure actor as the best example which I think is absurd. You have to choose a principle and of the New Hope principle's I still contend Hamill was worse than Fisher.
However, I also agree that by the end of the trilogy Ford was the worst only because he wasn't into it anymore.