Its been awhile since I've had a fish and I would like to get another one soon. Nothing fancy, just something simple and not too high maintenance.

I've always had bettas or goldfish so if possible I would like to branch out a little bit. Only thing is I don't really have room for the 10 gallon filtered one I used to use, so im left with a gallonish table top one and some large decorative bowl style ones. Is there anything else that I can keep in something like these without a filtration system?

Thanks for any suggestions!