There are good breeders out there, there are ways of telling if you are buying a pup from a backyard breeder ie those who breed just purely for money, and then there are good breeders, who breed because of their love for the breed, now, first, see if they give you a good written guarantee, second, check the prices for that breed, if you are getting a purebred dog for very cheap, chances are its a bad breeder, third if they refuse to show you the parents and their pedigree,I have 3 dogs(all were well priced with award winning pedigrees), one dobe and 2 GSDs, and all of them came with a 5 year written gurantee on their health, for congenital defects, for instance, GSDs are known for hip problems, my dogs are guranteed to be hip problem free, which is a congenital defect, my dobe, had a small minor problem, it has a detained testicle(which is not a major problem, could be fixed by a simple surgery), i talked to the breeder, and they were willing to replace my pup, but i am attached to that dog, so i didnt give it back, but the breeder still agreed to give me another dobe, whenever i want, that is a good breeder, as far as the dogs personality goes, they addapt to their owners, so if you are aggressive towards your dog, it will turn aggressive eventually, if you are lazy, your dog will just eat, sit around and get lazy,(unless its a husky, those are bred to run for 20-30 miles at a time) and its a fact, mutts are more unpredictable when it comes to personality, another thing, every dog needs some level of excersize, so if you keep your dog tied up all the time, it will get destructive when they are open, just teach em fetch, you just throw a ball, and the dogs run around, again, dogs are smart animals, so if your dog is aggressive towards you, its your fault, but if the dog is aggressive towards others, then its just being protective(its a trait seen in domninant dogs), you are the leader, you just always have to show them. as far as german shepherd being work dogs, yes they are work dogs, but they were bred for 2 reasons: 1 guard dogs 2: sheep herding, they were just meant to sit around, keep an eye on sheep, and make sure the sheep dont get attacked by predetor, so even then, they didnt run much, in reality, GSDs are very calm, its not the dogs that are the problem, its the owners. if you think you will be a good owner, then your dog will forever be loyal to you. after all, theres a reason they call em mans best friend.