As a former Military Working Dog Handler I'm going with what I'm partial too which is your good old German Shepard.
All German Shepards are full of what we call 'civil' or bark and growl.
They'll bite, but there mostly bark.
They are also fine with kids, and very obedient
An old west lawman once said when asked why he carried a .45, "because they don't make a .46"
God created man, Sam Colt made them equal.