I have two mutts (Colby is Canaan Dog and JRT, Tippy is border collie and German Shepherd), and one purebred (Mayberry, chocolate lab). I love them all equally, and find them all to be incredibly smart, sweet, and beautiful dogs. I don't prefer one of my mutts over my purebred, or my purebred over my mutts. I love them all because they've all got awesome personalities.
But I think if you're looking for a family pet, why not drop by a few local shelters? There are a ton of dogs that need homes - about five million dogs are euthanized in American shelters every year. 750,000 dogs and cats are gassed to death in Lousiana annually. A lot of these dogs are purebreds.