While our personal opinions on what dogs are the cutest — clearly, it's 1. mine, 2. all other doggos — may vary, I think it's pretty safe to say that on the internet, certain breeds get more attention than others.
Golden retrievers, pugs, and most especially, corgis. Which is understandable, since they match the (not really) scientifically proven rules of cuteness: big head, short legs, and tons of personality.