It might depend on the person. I kind of like mixed breeds because they are their own dog, unique. We have owned:
Lab mix: Friendly, good with family, even-tempered, fun.
Border Collie: Sweet, kind, loving, fun.
Boxer mix: Very sweet dog, athletic.
Poodle/Pomeranian: (owned by family member) Friendly, likes people, affectionate.
It can also depend on how you raise and treat the dog. We've had very good dogs. Our lab mix liked car rides, taking walks, and camping with us. The Border Collie loved everyone. Our dogs were part of our family and spent a lot of time with us.
I suppose there best dogs, in general, are the ones who are part of the family, do things with the family, get positive reinforcement, and are not ignored. Dogs who spend too much time alone or are scolded can up to be problem animals.