Try hyphessobrycon elachys for the small tetras. They actually have a different behavior, always displaying amongst themselves and are way more active than the other small tetras. They got a lot of sass in their small bodies.I am not a fan of the commercial livebearers, guppies primarily, cause... rape much? Messy, not that interesting body shape or behavior either, so no thanks. I had endlers and except the guppy hybird (yellow tiger) they were ok. I was planning on some Neoheterandria elegans or similar small natural livebearer, but I have soft water and couldnt find a supplier anyways.
I also realized I am not loving tetras. I always disliked neons, due to their overuse and poor genetics, but I have had ember tetras and they are just...boring, static, nothing interesting about them. The rummynose are a bit better, but the other tetras are mostly the same in my mind. Not all, mind you, I would love some koongo tetras, to see phantoms and their behavior. But the smaller tetras seem the same batch to me.
I used to be so excited for my corydoras and after some time I was so disappointed. Now in the new tank they are so active, always looking somewhere and I am loving them again, but will see if it changes like last time, where they just sit around.
I was also so deeply disappointed in my dario (I have the dario hysginon). I was so excited, and the fish is just so meh. Nothing interesting in its behavior, just the color can be really wow, but it is not enough for me. And they cant really coexist that well with other fish and I have no chance at breeding, cause no females, despite me getting a larger batch.
Males get really elongated dorsal and pelvic fins which they use for displaying
They just have more personality I find than the other small guys. Their lack of bright color is made up for with their bold personalities.