Most popular fish?

[Lupin]

Goldfish. Even kids scream for prized goldfish in carnivals.

 

[manlyfish]

i'd gotta say common plecos everyone needs a "suckerfish that eats dirt"

 

[knifegill]

Yeah, but if a stranger comes into your house, they are more than likely to ask what weird kind of "Goldfish" you have. The reality is that goldfish are the most known fish in the world, probably next to tuna. In children's literature, comedy, even art, if someone says "fish" they are probably thinking of a goldfish.