I agree with the sentiment that 100% alignment changes are meh.
Evil to neutral or neutral to good are okay, when they do the whole 180, it just gets plain out silly.
A character I liked was Snape. People arguing that in the end he was "good" are ridiculous. Redeemed? Perhaps, no way he was ever "good" though. His character was selfish, cruel, arrogant and spiteful, he was a deeply flawed man, who at the last fourth of his life finally started to take some right decisions.