Tibetan Mastiff: Renowned for guarding, aloof yet affectionate, expensive breed.
American Staffordshire Terrier: Affectionate but energetic, needs training, wary around children.
Giant Schnauzer: Protective and resistant to pain, high stimulation needs, may chase smaller pets.
Appenzeller Sennenhund: Cheerful Swiss breed, fiercely protective, needs space and colder climates.
Black Russian Terrier: Aloof but protective, requires strong leadership, large and potentially overpowering.
Chesapeake Bay Retriever: Naturally protective, stubborn yet devoted, requires regular exercise.
Boxer: Patient and affectionate, great with kids, needs frequent exercise and may have health issues.