The third season of Game of Thrones is almost the same as the third volume of the series of novels. It is just as good.
Game of Thrones is one of (possibly the) best fantasy series ever written in English. No major character is entirely good, and none is entirely evil. All are human, but with major character flaws. All have completely understandable motivations. This is one of the few series that gets it right. Despite the necessary presence of night walkers, of giants and dragons and sea monsters, it is centred on the people and their interactions. Love, hate and betrayal: human. Sex, money and power: human needs.
The format follows closely that of the book, with episodic development of the major strands of plot and character. By now, it's possible to see how this convoluted tale could end: there are only a few ways for all the surviving factions to come together, and this season is every bit a middle of the book season. It develops the threads of seasons one and two and adds a few hiccups along the way. Daenerys matures, as do her dragons. The Lannister dynamics shift dramatically. Jon Snow, Bran Stark, and especially Robb Stark have life-changing experiences.
Season three gives us what we expected after seasons one and two. Now we have to wait for season four. More of the same, please.