Ditto on the Jack Russel Terrier, the little one I have alerts us if somebody walks up the driveway and sits by the window most of the day when not outside. Other then that (2) 12G shotguns one in the house and one in the garage, (1) 38 Special in the bedroom, (2) 22 rifles in the garge, plenty of baseball bats and a machete hanging near my desk in the garage, signs warning would be intruders that I have dogs and I will shot first & ask questions later with motion sensored security lights mounted in the front & back yards.
While I'm home most of the guns are loaded and ready, while I'm away at work the guns are unloaded and safely stored, I have to depend on my dogs, (( also have a mixed Queensland Heeler/Terrier who will do anything the Jack Russels does), because my wife will not use a gun, (she is quick to say 911 is the answer and I cannot convince her that it may be too late waiting for those lazy bastards).
Hell, I carry the 38 when I drive more then 25 miles from my house......you never know and I do not want to be in a situation where I cannot defend myself or my family.