As much as I hate to say it, studies
have shown cats to have a higher thinking capacity than dogs. Their basic behavioral traits will reveal this. When a dog sees something it doesn't like, it will go after it, (regardless of it's size) giving a show of barking, growling, and teeth. A cat, on the other hand, only goes after something it both wants and knows it stands a good chance at killing, or it will run away. A dog won't run away until it's been "shown up" in a fight, or at least mildly hurt. A cat can actually evaluate it's fight beforehand. Not that they
all do, it's a general thing.
Not to mention dogs eat their own barf. I've never seen a cat do that.
Even so, I prefer dogs. Unless it involves laser pointers and a wall. Then it's cats, no question.
And of course, a scared cat on a leash is fun to watch. Their instinct says "escape" but they can't, so they play dodgeball with their bodies.
(Well, they can't easily be caught that way, right?)