NonUniformRationalBasisSplines is a basic modelling format that is nearly perfect for organic modelling. (However, I have just begun working with Maya's sub-D modelling option. It seems to blend polygonal and NURBS modelling technique.) NURBS allows one to model complex characters and the renderer only converts the model to polys once. I have found NURBS to be a very powerful technique for modelling virtually everything that I have needed.