I figure this is a good way to get the conversation going.
We currently have one community tank with a dwarf gourami, corydoras, neon tetras, a small colony of cherry shrimp, an assassin snail, and a plague of ramshorn snails that hitched a ride on some water lettuce we bought a few years ago.
Main tank is a mixed black water biotope - mostly SA, angels, sterbai Cories, otos, zebra plecos, rummynose and cardinals. I needed a home for a school of Congo tetras so they’re over there now too. I have an overgrown livebearer tank that’s mostly wild-type swords plus some otos and albino corydoras. Mixed community tank rounds out the permanent ones; Cories and otos again, a pissed off zebra plec that can’t be trusted with its own kind, giant danios, serpae and lemon tetras, and a mix of “survivors” who are the last few of their kind in my tanks. I keep a tidepool tank in the summer with native North Atlantic critters.
All my tanks except one contain what most think of as the plague, bladder & ramshorn snails.