I think the owner, and the way they are treated, goes a long way to determining the temperament and behaviour of a pet, especially if raised from a pup or kitten. So I don't particularly think either species is overall better than the other in terms of inherent "pet powah", and it comes down to personal preference.
I've had both in my life, but never really formed the same emotional bond with my cat that I did with my dogs. That and my dogs were bigger, so there was more of them to cuddle, and I loved taking them for walks. When they died, it was like losing close relatives, or children, rather than just animals. Which is why I haven't got another one since. I can't go through it again.