5) Fringe: Letters of Transit
As with last year, I had actually seen four of the five nominees on (or very shortly after) first broadcast, which left me with only Fringe to catch up with. It's not my show, and there were obviously lots of payoffs for narrative lines of which I was utterly unaware, but there was plenty of interesting stuff going on and one or two good lines, certainly enough to justify putting it above "No Award".
4) Doctor Who: Asylum of the Daleks
It gets really difficult after that. I loved all four of the other nominees and one gets into really spurious grounds for ranking one below another. My spurious reason for putting Asylum of the Daleks below the other three is that I didn't think it handled the Rory/Amy relationship well.
3) Doctor Who: The Angels Take Manhattan
Now it gets even more difficult. I loved The Angels Take Manhattan too, but my spurious reason for putting it below the other two is that the payoff for Amy and Rory's departure was a bit disappointing; they could easily enough travel away from New York to see the Doctor again.
2) Game of Thrones: Blackwater
Only one episode from the second series of GoT got nominated this year, but this was clearly the best set piece: an excellent chapter from the book, steered to the screen by GRRM himself. I felt the ending was fumbled, but otherwise really enjoyed it. I would not be at all surprised to see this win in San Antonio.
1) Doctor Who: The Snowmen
But my vote will go to The Snowmen, which ticked many of my fannish boxes, and has set up the mystery of Clara which we are still waiting to see resolved. I don't think one should be rude even to Sontarans, but otherwise I fully approved. In any case, I will cheer if any of my top four wins, and shrug in bemusement if the voters opt for Fringe.
See also: Best Novella