i'm probably biased, but i have to go with Fenrir Greyback. he was just, pure evil in such wonderfully horrible ways. *grins*

i also found myself liking Slughorn, although i was a bit dubious about him in the beginning. i loved the scene at Aragog's funeral.

i wasn't much impressed with the new Minister, but i don't feel like i got enough feel of him in this book, so, that could change.