3. Timothy Dalton in The End of Time
Say what you like about Timothy Dalton, the mans amazing. I know little to nothing about him, other than he might have been James Bond once and he was in that weird-a** live-action Looney Tunes movie, but hes still amazing. Especially as Rassilon. Ive only ever seen Rassilon twice: first in The Five Doctors and second in The End of Time, so I have no idea how he got from one to the other or even if hes in any other episodes, but I completely believe he was the same guy both times. His booming voice, indulgent theatricality and desire to live for all time (which will end in about five minutes if Rassilon gets his way) remain unchanged, with Daltons portrayal in particular embodying everything that was wrong with and corrupt about the Time Lords. In him you see the Time-War, Borusa, the Master (and guess who made him evil and crazy in the first place?), the Doctors trial for his life (both of them), the interference law and ridiculous hats. You see just how insane and selfish a craving for immortality is, and Rassilons power, both supernatural and over his fellow Time-Lords, just adds more threat and violence to this evil, power-hungry mastermind. Although the exposition of the episode is a little rushed (By the way the Time-Lords are evil, moving on) its more than made up for when Dalton appears. This Rassilon is out to destroy everything. And this time, without silly ginger mutton chops.