One of the best family dog breeds is the golden retriever. They have one of the best temperaments, are playful, and very good with children. Other dogs that get on well with children a labradors, staffordshire terriers, and pugs.
Although big dogs can be just as friendly towards children, their sheer size and strength make them difficult for children to control - especially on a lead - and they might end up hurting a young child simply by being playful.
If your family is after a small dog, a Cavalier King Charles Spaniel is a great choice. They tolerate children very well and are not as prone to biting and barking as some other small breeds.
Labradors and Golden Retrievers are also good with kids. If you have rough and tumble boys (like I do) the size of these dogs is actually quite good as the dog can tolerate the tough love sometimes dished out by little boys.
We have a Spanador, which is a Cocker Spaniel x Labrador that is the best dog we have ever owned. She isn't the brightest dog, but her gentle loving nature is perfect for the family. She is playful and energetic, but not as frenetic as any of the working dog varieties.
My suggestion is an American Pit Bull Terrier. These dogs get a real bad rap in the media but when raised with a good and loving family, pit bulls make amazing pets. They are gentle with kids and understand boundaries with kids, something other dogs often don't get. Pit bulls are loyal, often easy going, easy to train, loving and super cuddlers.
They are also big dogs and size can be an issue for some people or with some dogs, particularly if they have a high energy level. If you choose a high energy dog of any breed, it can cause problems. If the dog has a higher energy level than the humans in the house, it will quickly become bored and bad habits may ensue. I would highly recommend having a long family talk about getting a dog with the right energy level. You want to ensure the energy is lower than the laziest person in the house. Dogs look up to strength, and to them energy is often strength.
Most dog breeds have a mix of energy levels, and pit bulls are no exception. Energy level also influences temperament. Even choosing a low energy dog doesn't mean it won't be playful. If you are choosing a puppy from a litter, get to know the mom and her energy level. There is no guarantee that the pup will be like the mom, but the likelihood is higher. If going into a shelter, try and take the dog for a short walk. A walk can be very telling, especially after the dog has been cooped up in shelter's cage.
We had Welsh Pembroke Corgi's from when kids were babies until younger child was 12.
They were THE most beautiful dogs in temperament, very active & loved playing with the kids. Very loyal & marvellous watch dogs. No wonder HM the Queen has had them all her life!
If I were to get a dog, wouldn't go past a Corgi!