There are 169 breeds and names varieties of canine recognized by the AKC, American Kennel Club. Find them at AKC.org. There are 4 new breeds now.
Beauceron- this dog stands 24-27 inches tall at the shoulder and weighs to 110 pounds. This is a herding type of dog. This canine bread has been raised in France since the 1500’s. Currently they work as police dogs and as military guard dogs. An experienced owner is needed for this dog that does best as a partner with you. Beauce.org is the site I would have said to look at however it is all in a foreign language. Try http://www.dogbreedinfo.com/beauceron.htm instead for pictures of this beautiful dog.
Tibetan Mastiff- this dog stands 24-29 inches at the shoulder and weighs up to 140 pounds. Originally it was bred in Tibet for protecting monasteries, homes and nomads there. They are very loyal dogs and will do a good job protecting. Remember though that these dogs need a lot of socialization to be good citizens. Tibetanmastiff.org is a neat site that starts out quietly, took a minute to load but then rewarded with pictures of the wonderful dog and they sell items as well.
Swedish Vallhund- a smaller dog that stands to 13 inches at the shoulder and weighs up to 30 pounds. It is a cattle herding dog from Sweden. A good family dog when raised properly and is good with other animals as well as children. Beware because this dog will bark. Swedishvallund.com is the site for this small dog. Wonderful information and graphics you will find while looking through this site.
Plott – this is a medium size dog which is often brindle in coloring. They stand 20-24 inches tall at the shoulder and weigh in up to 55 pounds. Called a coon dog, they also will stand up to a bear or wild boar. They need to be taught really well since they are prone to wandering. Being bred to hunt that is hard to contain. An American dog and rarely found outside of the southern states of the US. Not really a family dog if you have not gleaned that already. http://www.dogbreedinfo.com/plotthound.htm
There are two more dogs being considered for registry. Dogue de Bordeaux found at http://www.dogbreedinfo.com/doguedebordeax.htm
and Norwegian Buhund found at http://www.buhund.org/
Any particular dog being included in the AKC helps to be able to participate in dog shows. More care is taken when breeding them also so that whims are not entertained in odd genetic matchings.
As always when adopting a dog into your family you must remember the temperament and care needs of such a canine friend. Training is very important as well. Too many dogs are taken to shelters when early and consistent training would have made for a happy life for all.
I hope you share your life with a dog and have found him or her to be invaluable.