Personally I'd go for a German Shepherd myself - they are good protectors and have a better reputation as family dogs (i.e they aren't prone to tearing babies to pieces).
My Grandfather loathed the breed to his dying day, for that very reason. When he was young they were having a big sunday dinner in the backyard. There were three babies in a crib on the back porch and a pair of German Shepherds from the neighborhood managed to get in the crib and kill two of them and seriously injure the third child before anyone could stop them. He held that grudge his entire life and refused to trust Shepherds again.
