Ten is my favorite because Tennant is probably the greatest asset and actor of the BBC. Maybe even history. Matt Smith is pretty good, but he can't capture the Doctor like Ten did. However, I think this episode is the best acting as the Doctor that Matt ever accomplishes. I was blown away by his acting in this. He came close in A Good Man Goes to War, however, I think he's brilliant in this. It's the only episode I would actually say in that his acting is on par with David's.