Book three and a half of A Song of Ice and Fire is really the second half of the third book, but I've read it a few months after finishing the first half, and thought it worked well on its own, being a length that felt more manageable to read in one go.
This is a really action packed episode in the story, full of unexpected twists and events that really shake up the ongoing storyline. I love how unpredictable the plot can be and how Martin can play with my perceptions of each character throughout.
I found my criticisms of earlier novels in the series swept away - the pacing was perfect, the points of view more at good intervals, and there was never a moment that I didn't want to dive straight into the next chapter.
This is probably my favourite entry in the series so far - it brings a lot of character and plot, and if the following novels are this good, I'm really looking forward to reading them.