Ok, since the board seems to be overwhelmingly pro-shaking, I`ll give you all a couple pointers.
First, get out a Sara figure and the Secret.
Notice how Sara is thinner than the box. So when you shake the box side to side you get allot of movement, and get the sound of soft PVC muffled by a plastic bag hitting cardboard; "Paf Paf" Also, due to the stand and various loose bits you get a "Rattle Rattle" along with that.
Now note how the Secret has a high stand attached, so there is very little clearance between it and the box, so there is very little noise when you shake it side to side; "shif shif" And being one solid piece of ABS there is no other noise.
Sara is fairly tall compared to the box, so only a slight bump when you shake top to bottom. Plus the rattle.
The Secret, on the other hand, is short and has plenty of room to accelerate to noisemaking velocity. And since its a solid piece of ABS vice PVC, you get a nice "Ka-thunk Ka-thunk" sound when shaking top to bottom.
So these principles can be applied to just about any figure. Keep in mind the material composition, physical dimensions, and parts count and you will never be surprised as to what you get. Weight alone is not enough to base figure identification on. Use your brain, and other senses.
Bariaburu Faita