12. Derek Jacobi in Utopia
When you think of a human incarnation of the Master, you may think of a power-hungry business tycoon, a behind the scenes crime lord or some kind of second world tyrannical dictator. You do not immediately imagine a long-suffering and lonely scientist working to prevent mankind from total annihilation at the verge of the end of the universe. Shakespearean-trained actor Derek Jacobi is on this list almost entirely because of how little you suspect this gentleman and scholar is in fact the evil mastermind that he is. His tears as he reminisces about his rapid and almost ignorant life and regret at allowing himself to become so aged and close-minded are so heartfelt and touch on an issue so rarely explored on Doctor Who (if at all) its impossible not to see the added touch of realism. Though I never really considered him to be that convincing as the Master, he sure delivered that shock reveal with merciless glee, and, needless to say, did a hell of a lot better than Eric Roberts. However, tired, disappointed Professor Yana is where the glory really lies in this portrayal, and he doesnt half leave an impact. Oh, while Im on the subject Id just like to point out that John Simm is not going to be on the list. Personally, I think of him as less of a guest star and more of a very high-profile actor who played a very high-profile part. And Im really sort of defining guest as two episodes or less, so there.