Most Common Dog Breeds: http://www.dog-breeds-list.com/most-popular-dog-breeds

Petfinder Dog Breeds (be sure to scroll down past the ads): https://www.petfinder.com/dog-breeds/

Animal Planet Dog Breeds (with video): http://www.animalplanet.com/breed-selector/dog-breeds/all-breeds-a-z.html

American Kennel Club Dog Breeds: http://www.akc.org/dog-breeds/

Dogtime Dog Breeds: http://dogtime.com/dog-breeds/profiles