Oh, that is VERY difficult, because so many things are great, but in so ma y different ways. How do I rate a camera/lens to a kitchen blender to a domestic (living room) HD/DVD recorder to a colour photo printer to .... well, you get the point.
For instance, the purpose (for me) of camera/lens is largely about taking photos to print, so the printer is critical, but without camera/lens I'd have nothing to print. Chicken and egg problem.