I like them both equally most of the time, the dog is only better for playing with and as a greeter. You cannot have a Chesapeake Bay Retriever sit in your lap while you play an FPS or RTS, it just does not work with a 70-75 pound dog; but a cat can and will sit in my lap while I play. It is nice to be able to get some quality time with the cat during load times. Anyway, I like dogs a tiny bit more than cats. One advantage to cats is if you have two you can watch them bicker every now and then. Better than the Coliseum...