I like cats better. I have a cat 
His name is Sandy and he's a lazy orange tub of lard.
Dogs smell horrible, especially when they get wet, they require a lot more maintenance and they are more expensive to own than cats.
For all of this you get a dumb puppet that does what you tell it to. I don't know about you, but I don't need that sort of control, I prefer cats because they actually have personality and intelligence unlike the idea of the "loyal" dog which just dumbly follows you around performing tricks on command.
Cats are some of the only animals that can learn behavior through observation. My cat learned how to open doors, but he gave up because he didn't have the arm strength.
TL-DR; cats win, dogs lose.
