Second this. When I was a kid I was a tropical fish nerd among many other things.

Betta easy and more interesting than gold fish. And, if you want to add more fish or get a bigger tank they can usually get along with others. As long as there are no other males.

Many years ago, I had an orange betta fish. It was super crazy; on two occasions it jumped out of the fish tank and almost died.

I hear good things. They are almost too elegant though.

I'm more of a goldfish kind of guy but from what I'm reading they are high maintenance.