Always love to see a well set up aquarium whether it's in somebody's home or in the dentists office waiting room. Fresh water, salt water, whatever, it's all beautiful.
Before I went snaky and got my first python I had 10 great years of various fresh water fish in my tank. Largest fish I ever had was a 14" iridescent shark (look like mini great white's) and a 16" pleco and those two got along just fine. Before them I had dozens of others but man, having a nice clean tank with healthy happy fish is a true labor of love and after 10 years and about 70 fish I was done. Had the T-shirt, read the book, the whole thing. Snakes are so little maintenance and it's great but I still miss the fish. My main regret was never taking any pictures!! DOH!
As an experiment, I once brought home a minnow from the river and decided to add it to the community
to my surprise things went very well from the start, no problems whatsoever. Fast forward about eight months and now the minnow is like a small salmon and he's aggressive as all hell picking on everybody.. This due to lack of foresight on my part. I eventually climatized her? back to river water and returned her back to nature in July.