We have a 10-gallon fish tank with glofish and neon tetras. (Used to have dalmatian mollies and flame von rios, but the glofish and neons seem to live longer in our tank and I have a 5 year old so... yeah.) I'd love to have a dog or cat, but my spouse is highly allergic (even to the ones that are supposedly hypoallergenic). The fish are fun, though. Kind of relaxing to watch them.