12. A Good Man Goes To War
The reaction to splitting the series in two for Series 6 was a mixed one but one definite upside of the move was that it gave us two finales for the price of one. While The Wedding of River Song is a fun ride, the first half of the series' A Good Man Goes to War was the superior episode. It's simply packed full of memorable moments and characters - Rory the Roman taking on the Cybermen in an amazing pre-titles sequence, the introduction of the Paternoster Gang and, of course, the reveal of the truth about River Song. With all this plus an interesting discussion of the Doctor's increasing darkness, this is one of the most purely exciting episodes of modern Doctor Who.