1. "One Day, I Shall Come Back..."
http://www.youtube.com/watch?v=Um5Cn5eHsGo And finally, for the greatest moment of the show, we go back to the start with William Hartnell, saying goodbye to his very first companion. This was a moment that shaped the show for eternity; the quiet emotion, the reference to returning home that Hartnell made in An Unearthly Child, and the grandfatherly performance. It's a masterful speech from one of television's greats - one that's tried to be replicated a thousand times over in this show - and from this moment forward, it felt like the adventure had really begun. Susan is the centre from which Who spins away even today, as the Doctor runs and runs away from his beginnings on Gallifrey. And one day, yes, we hope that we do see Susan again: perhaps she has a fobwatch, and has been hiding on Earth, or perhaps the Doctor visits her in the past. Here's to another fifty, and to more fantastic moments like these. What are your favourites? What would be your number one? Who's your favourite Doctor and what was your favourite episode? Comments below are, as always, most welcomed.