Both are good. Cats are definitely less effort than a dog (as someone who's never owned a cat at least) as they don't need walking or training particularly, if you don't train a dog it will be a menace, cats just do their own thing. I've got a dog and wouldn't change that for anything, the love and entertainment they give and the fact you have to go outside with them and exercise is great for your mental health. If I couldn't have a dog, due to not being able to exercise them properly cuz of work etc, I'd happily have cats.
I'd also like to recommend rats as alternatives, they are super sweet pets, very clever and social critters. The only downside is they don't live very long.
You can't take the sky from me.
Excellent theme tune.