I think I find any fish 'attractive' if it has a purpose, something that helps it do what it does eg. the monk fish, perfect for ambushes with a huge mouth, gar's for their streamlined instant strike speed, leaf fish, for their stalking, camouflage, then striking, etc. What I dont like is man-made modifications, that just look ugly and if anything, hinder the fish. How can that goldfish I pictured swim right? Just doesnt look right to me.