Seems like necroing this thread is reasonable, although the TV series has diverged from the books, and there has been a lot of TV discussion here.
So I seem to the only person who was actually underwhelmed by the Battle of Winterfell. There were some really good bits in there, and I enjoyed those bits, but the parts in between bored me. I think part of the issue was how it was filmed. A lot of the scenes were dark, up-close, ambiguous, and featured many cuts. Perhaps it was designed to show just how chaotic war can be. A lot of these shots were done with the Battle of the Bastards, but maybe that was less annoying because it wasn't dark.
As far as establishing atmosphere, the darkness and weather did a great job, but it wasn't great for me.
That being said, I enjoyed the highlights.
The Dothraki with flaming swords were a great-looking scene, though it bothered me greatly that their great tactic was to throw the horsemen into a battle with no support so they could be killed and come back as zombies. Actually, I'm not sure they were raised as zombies, but they might as well have been. The scene was beautifully shot, but I feel it was marred by the logistical problem of what they did.
Lady Mormont kicked ass. I loved her killing the giant. No complaints there. It's a pity she had to die, but honestly she had the best death.
I was vindicated when my theory that hiding in the crypt was a really bad idea when facing a foe that could raise the dead. Honestly, I think that scene could've been improved upon by everyone being massacred because that would be a really dark moment where the people who were in the "safest" part of the castle were wiped out. This scene was also foreshadowed by Arya giving Sansa Chekov's knife, though it was never used. That bugs me because why would Arya give Sansa a weapon only to not have it be relevant? Was it just jacking with our meta-knowledge? When they focused on Sansa and Tyrion, I was thinking that perhaps she would sacrifice herself by drawing out the zombies, letting everyone else escape the crypt. I guess I shouldn't call this a highlight since it was my biggest disappointment with this episode, but I can't deny that it was shot well.
And of course, Arya murdering the Night King. This scene was great. I wasn't fond of Theon throwing away his life with such a clumsy attack. They could've at least made his death cooler. But there was some good tension as Arya leapt to save the day, was thwarted in her attack, and then pulled a reversal to provide a satisfying end to the Night King.
The highs were good enough to make this overall an enjoyable episode, but it ranks lowest of the battle scenes for me.