4. Rose Tyler (Doomsday)
For the purposes of this, I'll be talking about the original departure, which was absolutely heart-breaking. Since then, Rose has been in and out of Doctor Who like a fiddler's elbow, which has obviously reduced the effect of the original departure. Especially seeing as at one point in her return she developed a lisp for a whole episode, which begs the question did they film her following dental surgery? Anyway, this is regarding her first departure. We knew that Billie Piper was leaving before the episode was aired, but even so Doomsday was a rollercoaster of an episode. We had Daleks versus Cybermen and the Doctor versus them both. That final scene with Rose with her hanging from the handle about to be sucked into the alternative universe was amazing and such a fitting way for her to go. It was chock-full of drama The Doctor got to say his goodbyes via a projection, which took all the energies of a dying star to power. The scene was emotionally powerful and the effect on him was evident, something made it all the more emotional for the viewer too as we'd never seen him like that. But just before he was about to say what I presume was "I love you", the message was cut off and he was left with tears in his eyes. Suddenly, Donna Noble got dumped in his lap. Rollercoaster of emotions doesn't come close.