I don't even know anymore
For me it's a three way tie between Spiritomb, Banette and Cofagrigus. All of my favorite Pokemon happen to be ghost type Pokemon. I love Spiritomb because they have the Odd Keystone and I think that is amazing. I love Banette because of their zipper mouth and I love Cofagrigus because its a sarcophagus which is cool.
TG