This is a tough one! If you're a cat lover, then you will confidently claim that cats are far more superior and intelligent than dogs. If you are a dog lover, then you will claim that your canine friend is better equipped in the intelligent stakes! The truth is it all depends on how you measure intelligence of an animal.
Cats and dogs are so far removed from one another as a species that it would be a minefield to try and distinguish a test that would be fair to both animals. For starters, cats are loners. They hunt on their own, where as if they had to fend for themselves, dogs would hunt in a pack. Cat's paws are much more dexterous than dogs because they have to be nimble enough to catch their prey such as mice. Dogs on the other hand can hunt down larger prey if they work together in a group.
Although both kittens and puppies grow at roughly the same rate, cats do toilet train their kittens. Dogs on the other hand don't. However, if you are looking for an animal to train and become a life-long companion, then you won't get better than a loyal dog.
The person who answered the above is obviously a dog lover, and not familiar with the fact that cats are loyal and are life-long companions just as much as dogs. You can train cats also, but having a companion capable of some independent thought and investigation of situations to determine what they will do, makes them more interesting and intrigueing than dogs, who are usually more predictable. Of course both are sweet and lovable if they've been treated right.