I feel that Theon has the best character arc in the books (only contestant being Jaime), and his chapters in Dance were the consistently best quality (in terms of writing and enjoyability) of anybody who got more than 4 chapters in that book.
I came into Dance "hating" Theon. He was one of the better written characters, but he was written to be unlikeable. Daddy issues, betrayal, needing to prove himself... good characterization, and makes sense, but I still wanted to punch him in the face as I listened to the things in his head. His actions in Clash ultimately helped break the back of the entire North, he led Cat/Robb to think Bran/Rickon were dead (and all of the bad stuff that came from that), basically doomed any chance of the Starks winning... I somewhat reveled in the idea of him getting captured by a despicable character so that he'd "get what's coming to him".
But then I read the first "Reek" chapter and it sickened me. I legitimately felt bad for my previous shadenfreude. And over the course of the book I actually came to really care about his redemption arc. Dance had it's flaws (basically anything in Essos not involving Barristan the Badass) but the Theon arc was fantastic and really does show how well GRRM can nail that **** when he's on his game.
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##Alec
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