The pet that requires the least interaction/involvement would probably a lizard; small animals, fish and birds are all more care intensive than one generally assumes. Fish would be the next best, but goldfish are actually very messy fish and take more work to maintain - you may want to consider a betta, as they are very simple to care for. In fact, a betta would be the least maintenance of any potential pet (other than a rock). If you are going to choose a small animal, consider if it is something you want to be able to handle regularly or an animal that tends to stay to itself. For a social animal, consider ferrets, rats, and guinea pigs; for less demanding species, consider a gerbil, hamster, or mouse. Chinchillas require special bathing routines and cleaning; ferrets may have an odor and require frequent waste cleanup. And lastly, large birds can be intimidating and overwhelming - be sure to experience their volume and personality before rushing into a purchase of one. Just my two cents.
M.
_________________
My thanks to all the wonderful members here; I will miss the opportunity to continue to learn and work with you.
For those who seek an alternative, it is coming.
So long, and thanks for all the fish!