This was probably the first episode of the "New Doctor" (Smith) I would rate as 9.5. I do not like the guy, I do not like his companion(s) too much - I think they all lack the charisma of the previously two doctors. But this episode was just plain great.
I make a habbit of not reading a summary prior to watching the episode, I do not know a lot about writers, I just enjoy a good episode or dislike a boring / sensless one. So this one was a very nice surprise, giving a brilliant idea about the Doctor and his 'Wife'. I find the title very fitting.
There is not much to say in addition to the folks who have given their opionion before me. Just one thing needs to be mentioned that was not made more prominent and which I find rather nice. As the Tardis starts to communicate with Amy and Rory she asks the Doctor "The pretty one?". And from there on it was clear that the Tardis would talk to Rory - we all suspected. Only the Doctor was surprised. So, finally, Rory gets his bit of attention from the one that matters, the Tardis. Thank you, author, for this pice of attention!