Who Is The Doctor, by Graeme Burk & Robert Smith. Paperback.
I am a sucker for TV episode guides, having read them for 24, Alias, X-Files, Babylon 5 and many others. As a huge fan of Doctor Who, when I saw this book, there was no doubt I would pick it up. This one is different from the rest of those, in two key ways.
First, in addition to episode trivia and production details, this book includes critical analyis and reviews of all the episodes covered -- the book includes all the episodes of the New Series thru the end of Series 6, "The Wedding of River Song." This means that negative commentary is present where appropriate, and as any fan of the show knows, there are a few episodes each series where negative commentary is deserved. But this evenhandedness has the effect of emphasizing the positive comments. These review and analysis portions make up close to half of the text for each episode entry.
Second, the book is written by a pair of co-authors, and having a second set of eyes discuss the episodes adds depth to the analysis. Each episode entry has a main review written by one of the authors, and a "second opinion" section where the other author has a chance to rebut, disagree, or simply bring another perspective to the episode. Certainly they tend to agree on the best and worst episodes, but the cases where they disagree tend to be quite entertaining. Both authors are huge fans of the show, meaning they get into their fair share of petty arguments. And even where they do agree, the second perspective adds insight to the reviews.
This is one of the finer episode guides I have run across for any show, and highly recommend it for any fan of the ninth, tenth, or eleventh Doctor.