2. The Mastiff
This breed is one of the all-time favorite dogs for family pets, but this dog is not high on the list of intelligent breeds. Considered to be a “big-hearted dog” and well-behaved, the mastiff is considered to be untrainable and clueless to some standards. When a dog presents qualities such as these, it can be a frustrating situation for the dog and for the owner; making training almost impossible. By all means get this breed for the family; just be aware that training might be something that can get to your nerves.