I grew up with both cats and dogs, so I like both. I give the edge to dogs because dogs love their people. A dog would die to protect its human, a cat would not. There have been stories of dogs refusing to leave their owners’ graves. This type of devotion and love is not found in cats. I know that dogs are not for everyone. Their affection can be smothery and too much to deal with, cats’ periodic need of affection may be preferable since it is not demanding. Plus, the constant devotion of a dog may be seen as valueless, because it is always there. A cat’s affection is not so reliable, it is more variable, so may be seen as more valuable when the cat deigns to give affection to his human.
I will say that people who prefer cats often think they are more intelligent than the hoi poloi who prefer dogs (I am referring to hipsters).