Star Wars: The 11 Actors Who Played Darth Vader
7. Hayden Christensen - The Fallen Jedi
His performance (or, more accurately, George Lucas' direction of his performance) may be heavily mocked, but Hayden Christensen still wound up getting to bring the most pivotal part of Darth Vader's transformation to life - his fall to the Dark Side.
On top of playing the pre-suit Anakin/Vader, Christensen was also the person under the mask during Revenge Of The Sith's final moments. As he's much smaller in stature than David Prowse, this led to a redesign of the costume, with extensive stilts needed.
He also played Vader in some new shots for the revamped version of the Emperor scene on the 2004 DVD release of The Empire Strike Back (and all subsequent releases).