Rottweiler
The Rottweiler is directly descended from the early mastiffs, so it shouldn’t come as a surprise that they are also loving and low-energy dog breeds.
I know there are lots of misconceptions circulating about Rottweilers, but in reality, they are really affectionate. As for protections, oh, they certainly deliver.
Even if they bark sparingly, when they do, the volume of their voice will let any stranger know that they shouldn’t get near you.
And if you’re curious to know more about their ability to protect, it’s worth mentioning that their intimidating stance and demeanor are generally meant to keep bad people away. Rottweilers possess the needed courage to step in and confront potential abusers.