I prefer dogs to cats. I don't have either as a pet, though my best friend has a dog. My past history with cats has been kind of awful, due to both being scratched, and being allergic to them
They both have cuteness factor, and I don't really think one is cuter than the other. There are adorable puppies, and adorable kittens as well. But cats generally have that "I am too good for you" attitude, whereas dogs generally just want to love all over you. From what I've seen, dogs are often more intelligent than cats as well.
I think I may be the only person on earth who doesn't find pugs adorable though...