I loved the dogs in those pictures. Not surprised at any on the list. I've owned or fostered almost all of those breeds at one time. I haven't had a Boxer or Poodle yet. I have to say out of all of them I am slightly partial to the Beagle - such a fun breed and wonderful family pet.
EDIT: I would think Pit Bulls only just missed the top 10; I see them all over.
'Pit Bull' isn't a breed recognized by the AKC. There're a few distinct breeds that are called pit bulls colloquially, and mixes of the breeds are also called pit bulls.
But it looks like the Staffordshire Bull Terrier and American Staffordshire Terrier are the 76th and 79th most commonly registered with the AKC.
It's kinda a stereotype--but I doubt most pit-type owners are the most likely to be registering their dog, also.