I would never own a Pit Bull or allow my children to play in a home that had a Pit bull. I'm sure it's true that not all pit bulls are bad, but whenever something bad happens, it usually involves a pit bull. (Bad dog accidents, that is).
That said, I am personally afraid of most aggressive type dogs like Pit Bulls, German Shepherds, Rotweillers, Dobermans, etc. My brother was attacked by a large mixed bred aggressive dog when we were kids and my dad severely injured when he tried to free my brother. So I'm a Shih Tzu fan!