1. No dead fish - in fact, healthy, thriving fish!
2. Healthy plants. My own philosophy of plants is to provide a "natural" environment for fish - to make them comfortable and add some beauty and occasionally a little extra $$$ on the side (as evidenced by my recent selling of three tall Barclaya Longifolia plants from a pruning, which yielded $27 in LFS credit). Plants are an afterthought.
3. As little maintenance as reasonably possible.