Like so many others, I went for "The Runaway Bride."
I've listened to the narrated audio of "The Feast of Steven." Maybe it works better with the full visual component, but on audio it, like a lot of the goofier late Hartnell stories, comes across like a stiff old man trying to tell a joke.
"The Unquiet Dead" is just so sterile; not even Eccleston, Piper, and Simon Callow can bring it to life.
"The Christmas Invasion" works surprisingly well for a story that sidelines the Doctor for 45 minutes. It's easily my second favorite.
"Attack of the Graske" is a fine game, but the poll says "episode," so...
"Out of Time" is one of the better episodes of Torchwood's first season, but all that really means is that it executes its warmed-over premise well rather than poorly.
"Voyage of the Damned" is the sort of thing I admire rather than enjoy. I can't find anything substantive to complain about, except that its reversal of disaster movie paradigms is not as fresh as it seems to think, but it all feels a bit hollow, without the emotional impact of the other new series Christmas specials.
And then there's "The Runaway Bride." It gets the balance perfect: a big action story, good character arcs for the Doctor and Donna, and great comedy. Donna is exactly the right character to come into the picture right after "Doomsday," and Tate demonstrates the same skill and range that would earn her so much praise in series four. The new series Christmas specials aren't really my favorite type of episode, but regardless of that "The Runaway Bride" is a clear success.