1. German Shepherd
5. Small Mutt with High Pitch Bark
6. Great Dane
7. Your choice here.
Female Boxer with small male french bulldog as backup
You left out Chow Chow. If you hear it bark it's too late.
If you want more gun control, use both hands.
#4 sucks as a guard dog. I've had a couple and you could walk in my house and pack off what ever and the dog would lick you as you left. I have a #5 female now and look out!!!!
My Henry is a ROTTWEILER.
If I had a #5 I'm sorry to say it wouldn't last long as a guard dog. Because it wouldn't stay in the house for longer than it took for a free dog ad.
Can't stand 'em. My GSD was a superb watchdog/guard dog. I don't think she ever really slept. Unfortunately she developed grand mal seizures and had to be put down.
Properly trained #4. If you are not a trainer, don't get one. #7 research the Dutch Shephard.
Define "Guard Dog". "Early warning system" to alert the armed residents that they should be flipping on the exterior floodlights and manning the gunports? Or "first responder" that is expected to leave a bloody mess and the armed residents are his backup?
First scenario almost any dog that barks at strangers will do.
Second one, look into the bouvier des flanders, they are gentle and fiercely loyal to their family, but will defend their family and territory like no other dog I have ever seen. IIRC, they hold the record for scaling a 16 foot wall. When used as herding animals, they body block the cows and sheep to control them. A friend of mine had a white one, about 160lbs. When he was agitated he jumped straight up and down, bouncing up higher than the chainlink fence. Their jaws exert over 1000 lbs per square inch force and they don't let go. Human bones snap around 350. They do require above average commitment to their training and grooming though.
I have to agree that #4's generally suck as guard dogs. However, if the burglar entered the house with a well bred #4 - the other guard dogs would all probably take a hike. IMHO I personally believe the Fila Brasilero or Neopolitan Mastiff are at the top of the list of guard dogs even though it depends more on the individual dog more than the breed. My favorite breed is still the #4.