Even the greatest actors struggle with a ****poor script and awful direction.
Yup, not all the big name actors could even save Batman & Robin from being a steaming pile. Personally, I'm not sure a different actor would have made much difference in Anakin's role. I'm definitely a Star Wars nerd, but I do remember literally cringing in the theater at some of the god-awful dialogue between Anakin and Padme.
Side note, ESB is my favorite as well.