Most personable wet pet type fish for a 20 long?

So I have a 20 gallon long I’m in the process of cycling. Unfortunately I am limited to this and can’t upgrade. I have a lot of experience with bettas (and love them) but want to try something different.

I guess what I’m after is a centerpiece type fish that has a lot of presence. I’d ideally like to keep one or two fish that are like wet pets. More of a gentle but curious personality (not territorial), and that would greet me at the tank or beg for food. Is there any fish that would fit this criteria?

A golden wonder killi fish can learn to respond to its owner and it can also be kept a a single fish.

An appiatograma., though i dont have a spicific species to recomend.

For some reason all the charismatic fish I can think of are also a bit territorial. Cichlids, angelfish, etc.

Never had one but these are cool looking fish

Paradise Gourami Fish Care - Macropodus opercularis