I had to leave my cat behind at my parent's house. I'm now living in a room of a house with a dog, and I've had dogs close to me for the majority of my life.
With dogs, you need to get them to think of you as some sort of leader. At the point they actually behave themselves, they're so submissive it's freakin annoying. Understand, I have dogs in my life I love, but I don't actually like living with them.
Cats, while not completely capable of fending for themselves in modern life, at least in practical terms; did for thousands of years, and still do in some rural areas. Cats are content with lying in the sun, eating, sleeping, and sometimes like to come and hang out. They amuse themselves rather than depending on people to survive doldrums (but will play with people too).
They're basically ideal roommates. Yeah you have to change the litter box, but it's much less disgusting than having to grab little baggies of poo. It's basically like having a roommate and being delegated clean the bathroom.