Best dog I've ever seen with a child is a Pug. My daughter used to lay all over and hug that dog when she was a toddler. He never snapped at her. Not once.
Best dog I ever had with a child was my German Shepherd.
I've had collies, Akitas, Shelties, and labs. My Shepherd once met a two year old that kept hitting it. She just kept looking at me in a pathetic kind of way. Sweet, sweet, sweet.