Cats are independent, so they're good pets to have if you don't have too much time at home to devote to one. You can just be near them and that's enough attention for them. For that reason, I like cats.
But dogs are wonderful too, especially if you have a lot of time to spend with them. The love you get from a dog is unlike anything else in the world, purer than human love. I can't imagine my life without it.