I have two dogs and a cat. Cleaning out a litterbox isn't difficult -- no worse than picking up doggie doo. Where I live (an apartment complex), they supplies us with doo-doo bags and we're expected to pick up after our dogs.
Cats can be left alone for a day or two (with food and water, of course) -- dogs can't. Dogs are noisy, cat's aren't. Cats purr; dogs don't. My cat fetches paper *bleep* the same way my dogs fetch their toys. Dogs wags their tails; cats don't (that I know of).
Yeah, I love cats. I also love dogs. That's why I have both!
Definitely, a dog hands down. I don't like cats. Dogs are mans best friend. Plus, dogs go outside to go to the bathroom. Who wants to clean out a litter box?