Reinhardt.
I hate that his shield is attached to him, and if I so much as twitch suddenly everyone behind me is exposed. I hate how close you have to be to do anything, because I can never manage to get any kills or get out when I inevitably start getting shredded. I just cannot f*cking play him for the life of me. And yet, when faced with a Reinhardt on the enemy team, I explode into a majestic ketchup if he so much as breathes in my general direction. 