I didn't answer your poll because I think it really depends. We bought a purebred German Shepherd puppy because we had a very specific need for our dog. We needed a dog that was intensely loyal, obedient, and with a shepherding/protective instinct. We have a lot of moose and some bears in our area. We live in a wild, wooded area. German Shepherds are known for being very protective of their family, especially children. Our pup is now 9 months old (he's HUGE and GORGEOUS). He never, ever lets the kids play outside without him.
I feel very good knowing he's out there with them, in case a mother moose and her calf would come wandering through or a bear.
He also trained so quickly and is so eager to learn new commands and do work.
The breeder we chose keeps the parents on site and spends a lot of time with the puppies. She knew we had 4 young children and chose a puppy that had a very easy-going personality. He's just perfect for us.
We do plan to get a second dog in a year or two and we plan to get a mixed breed from the shelter. Mixed breed dogs often don't have congenital health risks. Our local shelter works really hard to guage the temperament and lifestyle of each dog and works really hard to match them appropriately.