i prefer natural animals, they way they were meant to be in nature. all the fish i have right now are natural strains. silvertip tetras, a red honey gourami (the wild strain of honey gourami, there are a few other color variations) otos, and my ctenopoma acutirostre. my cat is a mutt, and my rats are mutts i saved from the feeder bin. yes, my rats are color variations not found in the wild, and somewhere in their history they were bred to have the colors and markings they do, but overall mine are just mutts, even the one dumbo i have.
i am not really against breeding for variations in color. color occoures naturally and they just breed certain animals together that desplay the specific color traits they want to make that color stronger and more dominant.
however, i think that physical deformities that some moron decided looked kind of weird and cool, should not be bred. like the oranda, bubble eye, celestial eye, etc. goldfish, or the baloon mollies, blood parrots in general, etc. i think they are all ugly and deformed.
longfinned varieties of fish is also different, because just like color, they just breed together two fish that naturally have extra long fins, and continue until they get a longfinned variety. the fish can still function and move and eat and see, unlike many of the goldfish varieties, blood parrots, etc.