I'm saying cats.
I've had cats all my life, and had to give up every single one of them Due to either death, or had to leave them behind, or couldn't take them with me in my new appartment *sigh*.
Luckily I can still go and visit "my latest" cat at my ex his place. Though, I guess he's not really my cat anymore

I'm not a very responsible person when it comes to things like that, I could never walk a dog because "I have to".
I do like dogs, the big furry ones, lol (golden retriever, collie, German shepherd, etc ...) wouldn't mind owning a dog, as long as it's the other persons responsibility

That's why I like cats, they are independant, can take care of their own perfectly fine, you just feed it, and most of the time it just pisses off
Though, "my" cat is so tame and lazy, all it does is sleep 23 hours a day.