5. Human Nature/The Family Of Blood
Something that marks out the very best of the revived series' episodes is how they turn the show on its head in some way. A prime example is this Series 3 two-parter which sees the Doctor become human. One of the best arguments for stories being more than one part, these episodes are supremely-plotted and allowed to breathe and build over their running time. The John and Joan romance is yet another well-done love story featuring David Tennant (the ol' Romeo) and the Family of Blood make for great villains, ably supported by the eerie Scarecrows. What's more, the story even finds time for some mediations on prejudices of the time and the tragedy of World War One. In short, this is a Doctor Who story that's top of its class.