Acara, angelfish (if deep enough), puffer, giant Betta, ram, convict, there’s a couple of options...not sure if any of those fit your taste...if your thinking larger fish like a Jack Dempsey or green terror they wouldn’t work in such a small tank
Do it nice planted with rocks and drift wood sticking out from back and tie anubias on the drift wood. Do pea puffers! Get a male and about 5 females. If you do rocks sticks and plants right youd be golden.