I do have a favorite ! he is a pink/red vt, my only vt. He is the smartest one, because he is the only one I was able to teach tricks. When I put my flat hand in the tank near the surface he swims over and lies on it and he lets me pet him with my finger. If I make a circle with my fingers (like a hoop), he swims through it. I saw that on youtube and so far he is the only one I've been able to train. He caught on in a matter of 5mins. What I did was that I would put freeze dried blood worms on my hand and he would have to go on it to get them, as for the hoop I rewarded him whenever he swam through. Now he automatically does it all the time even when there is no food involved. I just got 4 new ones that I ordered from a US seller on aquabid, still getting to know them.