1. Cracks In Time (Series Five)
Steven Moffat had a lot to prove when he inherited Doctor Who in 2010, and he clearly knew it. Adopting the formula of Davies' series for his first year a straight run of 13 episodes, some standalone stories and some two-parters he also decided that the story arc should stay too, and his was the best of them all. Not a repeated, largely meaningless term that only applied to the finale, nor a too-heavily focused, convoluted mess of ideas that largely fell by the wayside, the Cracks in Time arc is simultaneously a series-long story in its own right and a series of developments just subtle enough to allow the various episodes to be enjoyed by themselves. In short, it was a triumph. It's exciting; things change throughout so that Amy Pond gets an entire, three-episode mini-arc of her own later in the series as the crack erases all memory of her deceased husband Rory. We gradually learn more as we go, rather than having it all dumped on us at the end; the Weeping Angels are scared of the crack? Wow. It was caused by the TARDIS exploding? Holy cow. It can erase people from time but time travellers alone will retain memory of them once their gone? Interesting. In fact, this latter plot twist served a greater purpose for the show as a whole; the Earthlings of the Whoniverse had gradually become somewhat jaded by the notion of intelligent life beyond the stars - they see it every other week (to the point where they readily leave London at Christmas time in anticipation of another invasion). Moffat wonderfully restores some semblance of wonder and mystery to the world as we can now assume that many of these incidents have likely been erased by the ever-present cracks, thus forgotten about, and as such the people of Earth can go back to being actually surprised when aliens turn up. Amy can't remember the Daleks, after all, and nobody remembers a giant Cyberman traipsing around Victorian London either. Ultimately, of course, this all builds up to possibly the most perfectly crafted, moving series finale in the show's history. Everything comes to a head in an epic, celebratory romp spanning across time and featuring every monster the show has ever had (or at least the ones who's costumes were still knocking about in the BBC wardrobes). The beginning of the Moffat era came to a beautiful close, and although it was all up and down from there, at least we got one masterpiece out of it.