Everything (humans, plants, animals, objects, etc) basically hold energy inside of it (intrinsical energy). And lets also include the energy that surrounds every objects, which is the intrinsical energy which is viewed as the intrinsical energy being emitted (extraneous energy, also known as the magic term / phenomenon 'aura').
If talking about better or worse, it actually depends.
If observing objects made by various materials, Hexen is right. Materials which are associated with nature contain more effective intrinsical energy, and also emit it intrinsically.
If talking about materials and items that we affect with our own energy in life, it comes to the 'depends'.
We emit energy, manipulate it, send it, and of course that charge things with it. If we charge and item, it can contain more effective intrinsical energy than a material which naturally contains moe effective intrinsical energy.
It all depends on what affects the material / item during life. See this as difference between nature to external affects.