Most Overrated: Jeff Hardy. He can barely talk, and is still praised for his WWE time. Well, I also have heard that he is unsafe worker. His matches are entertaining, but damn, this is only good thing about him.
Underrated: I think The Pope. He is a great talker, a great wrestler and he has a mountaints of charisma. And yet, he is only thrown into stupid storylines like this with Samoa Joe and Okado, or this one with Devon. Give him freaking TV title, I bet he'd make the belt worthy.