I think if you are aiming for a little less work and want to go with something caged, a rabbit, rat or guinea pig are all good choices. A small dog is probably what I would recommend though. I always had big dogs growing up, and I still have a soft spot for them, but since my girlfriend and I have had our two little rascals, it is hard to imagine dealing with a big dog again. Small dogs are easier, especially in an apartment situation. We have a shih tzu male and a lhasa apso female and we love them both. They just had puppies last week.