I've purchased a number of small critters over the years (rats, hamsters, parakeets) with dreams of them being loads of fun to interact with. However, when it comes down to it, they are all too small, fragile, and skittish to gain much enjoyment from.
I'm also not interested in getting a dog or cat, which I assume would be more enjoyable and interactive. My family never had a dog or cat, so I have almost zero experience with them. I once babysat my brother's dog Sophie when she was a puppy for a couple weeks. She's cute, but I just didn't "get" the whole "man's best friend" thing. I don't dislike dogs, but the constant pleas for attention didn't seem like much of a friendship situation. I guess I'm just odd that way.
That said, from now on I think I'll stick to animals that can be used for, or produce, food. I've really enjoyed having the chickens. I love watching their antics, they are super low maintenance, and their eggs are delicious.
While I can't fulfill all my livestock dreams at my current home in the city (mostly due to ordinance issues, not lack of space), someday I see myself having dairy goats, meat rabbits, ducks, turkeys, geese, and bees. At the moment, I'm especially excited about the bees. I'm pretty sure they are legal in my city...more on my bee-dreams soon!