Pets vs. Human Life
It's better to keep tropical fish. (1) they are silent (2) you always know where they are (3) most of them never bite (4) it costs almost nothing to keep them fed. (5) they are beautiful to watch and ask almost nothing in return (6)) filtration systems take care of any waste product (they cause no damage to your furniture, carpet, drapery, etc. (7) they never complain, bark, meow or whatever (8) you don't have to walk them and pick up their piles of crap or clean out a stinky cat box (9) they may not be "cuddly" but they do enjoy nibbling on your fingers (8) with an automatic feeding device you can leave them alone for weeks, and they don't get depressed (9) when one of them dies it just goes down the toilet (10) they do not leave hair all over your furnishings, do not require baths, combing or other grooming (11) they never annoy your neighbors (12 you can move them about with a small net -- no need for pet boxes. (13) they do not smell up your apartment (13) they do no drool. So, if you are thinking of having some kind of pet in your abode, give consideration to fish. You'll be infinitely stimulated as they move through the water, as if flying through an unseen atmosphere.
For those who cannot do without something furry to cuddle, I might suggest a faux fur. I have nothing against small animals such as cats or dogs, I just wouldn't want one of my own. As for the argument that these animals give you love, compassion, guardianship, etc., I would suggest that you find a human mate that might provide some (or all) of these pleasures. If you cannot locate such a mate, I think there is something intrinsically wrong with you. I would posit that you're interaction with human beings has been so negative that all you can call upon are small mammals. There are a million humans looking for human connectivity. If you cannot link up to at least one of them, you've got a big problem.
Okay, it's fine to keep a cat or dog in the house, but if this becomes a surrogate for a child... well, that's another issue entirely. And I've seen many (mostly women) treating their pets as if they were indeed children. And we've all heard the bizarre stories of people (mostly women) leaving their fortunes to their pets. If you are rich enough to buy your pooch a diamond collar -- what are you thinking? There are thousands of people in third-world countries who are surviving without food and pure water. Where are your priorities? Can your pooch survive without a diamond collar? Americans spend more on their pets than they donate to charitable causes. I'm not saying let your animals starve or even stop enjoying canned delicacies. Just try to give things some perspective.