I disliked Dustin Byfuglien when he was on the Blackhawks. Not necessarily because he wasn't a good player - more because he is, and how damn self assured he is about it. Drove me insane. He's the personification of the type of player who annoys the hell out of you when he's on the other team, but when you get him, well, you want to rub everyone else's nose in how good he's playing. You become that fan that you used to hate.
And I think I'm ok with it. It's hard for me not to be after witnessing this in person: