That's what the whole season was leading up to. Like A Clash of Kings, season two of Game of Thrones has had a slightly aimless feel; while I think David Benioff and DB Weiss made changes from the book that improved the storytelling, large chunks of the season (read: Jon Snow and Daenerys) felt like the treading of water. But with the biggest engagement of the War of the Five Kings so far, the season has come together in a really satisfying and exciting hour and change.
Neil Marshall directed the episode, and you could see his touch in the sheer number of limbs hacked and men halved. I've felt that the show's scale is often off - we'll see two dozen extras passed off as a big crowd or an army - but Marshall made everything feel much bigger (even if the land battle gave the impression of taking up roughly 10 square feet of shore). And bloodier and more brutal.
All of the character stuff was pretty top notch. Again and again I've said the show is strongest when it gives each storytline more screen time, and Blackwater is set entirely at King's Landing, giving those characters ALL the screen time, and the result is a mini-movie. I don't think Cersei on the throne with Tommen would have been so good if it hadn't followed more leisurely moments in the holdfast, as the queen regent was getting up the liquid courage to suicide everybody.
I especially loved the way the Hound's story played out; him telling Joffrey to fuck off was quite satisfying. And Joffrey's cowardice is like a small comeuppance; you would have had to respect the little shit if he had actually led the forces into battle himself.
Joffrey's refusal let Tyrion take the glory in the end, and this is where we saw one of two major changes from the book (the way the Blackwater Bay stuff played out was much more streamlined in the show). In the book
(SPOILERS, I GUESS)
Tyrion has his nose sliced off, and I was curious if the show would go so far as to grossly disfigure its star. The answer seems to be no, and Peter Dinklage will be wearing a handsome scar in future seasons.
Some other highlights: Bronn and the Hound were great together. At this point it's easy to forget how irrittating Sansa was in the first season. Joffrey making Sansa kiss his sword is just the latest in a series of endlessly weaselly things Joffrey has done. I know a lot of you were hoping he'd meet his end tonight - no such luck. Tyrion has some amazing lines this episode, but the Hound's ”Any man dies with a clean sword, I'll rape his fucking corpse!” takes the show for me.