If you have the money, Anton's Changing Ponytail with the Expansion pack. One model that can create virtually ANY style you are looking for. (Check out the pics at DAZ, it does more than just ponytails.) I use it almost exclusively, except for Mehndi's braid. Vairesh also has some great models, if you are looking for multiple models. But since you asked for the one, it has to be Anton's. The MOST versitile hair out there right now.