My vote will go for a less conventional breed provided you have the room for one. Great Pyrenees all the way. All you will need is a warning sign Guard Dog Do Not Approach and you are good to go.Make sure your homeowners-renters insurance covers the breed you want as some don't
While outwardly they appear to be large fur balls, which they kind of are to those they have bonded with. But let someone come In unannounced and Houston we have a problem.