Sirius Black

Coming from one of the oldest (and darkest) of magical families, the rebellious Sirius Black chose not to follow in the footsteps of his other family members, many of whom became Death Eaters.

Harry's Godfather

Harry thought his godfather escaped Azkaban to kill him. Isn't that such a sad thing to think about. Thankfully, Harry didn't hurt Sirius and learned he was best friends with his parents. Before dying, Sirius became a father-like figure to Harry.