I love fish. Both to eat and to keep. I worked at a pet store for a long time and my job there was basically being a tropical fish expert. I learned so much and it gave me an "aqua thumb", of sorts, so now all fish under my care stay alive for years
Goldfish and koi I'm rather eh on because they're filthy and require a lot more room than most people give them. Tropical fish for life. Let's go Team Cichlid, Team Gourami, Team Livebearers and so forth. Speaking of Livebearers, Mollies love to nibble your fingers the way you mentioned and it's adorable.