Hi, I'm new hear but I've had every single animal posted. I currently own 1BP, 6 Cresties and 22 Leopard Geckos. As you can see, I'm partial to the leopard gecko. All of them except the Bearded Dragon are nocturnal so you can't really see them until lights out. Crested geckos don't require much heat (60-80 degrees) and are fairly docile. Leopard geckos need heat but are just as docile as the cresties and are prolific breeders. Ball Pythons are neat since they're SNAKES but can be little boring during the day. Bearded dragons require tons of food and are super tame but don't move much at all (you can leave them on your CPU and they won't move for a long time). Ultimately, which ever one you get, you'll come out winning since all of these are great choices.