A Storm of Swords
I had thought that this was the conclusion of the entire Song of Fire and Ice series, but aparently this is book three of seven. In any event, the story picks up right where A Clash of Kings ended and then proceeds to barrel forward with a renewed energy that seemed to be missing in the second book. The main story is nowhere near done, but many of the characters finally seem to reach a major goal/pay-off in the end. Onward into A Feast for Crows!