I picked personality as my answer. But there is way more to it then that. My favorite thing about the fish i choose to keep is by far there personalitys. But i wouldnt buy a fish i thought was ugly either. I a variety of different fish from small to large is size. My two favorite fish i have ever owned are a ceylon puffer which is bright yellow when happy with the green swirl pattern. And my large jardini which is oviously alot different in the loods deparatment. Bright or dull colors isnt the quistion more of the patterns and personality of the fish. But what draws me to fish as a general statement. Is watching them calms my agro but down. And i allways have had tanks in my room ever sence i was a liitle kid. And the water sound is allways very relaxing to me. I cannot sleep with out the sound of running water. I would never buy a fish because it was rare or hard to optain. Just to think i was cool and own something no one else has. Im deffenitly not that shallow of a person. If it is rare and i like it thats different. Such as a blue base golden cross back i would love to own. But not because they are rare, exspensive, or i cant own one. Simply because they are my favorite fish of all time.