Although I really, really dislike Dogs, it has to be them. I'm a cat lover, but admit that not all kittens are born cute. Humans are just alien looking when they're born, and the plates in their heads look all gross.
I think that is is equally split between Kittens and Puppies... Human babies are in generally quite ugly at birth (although everyone seems to think they are cute which is a mind **** as for the most part they all look the same ).
I do still also think babies are cute when they are young. When they are at the stage where they walk around just wearing a diaper I think there pretty ugly and flabby though. Then they get cuter again after that.