Depends on the impact of each one is able to cause in the society.

That depends upon what you mean by "ability".  Both case reports and original, I presume you mean "research" articles are valid and useful forms of publication.  A case report appears higher on the evidence pyramid than a scientific study, because it is a direct documentation of evidence, but an original systematic review, which is a form of original research article, appears very near the top of the pyramid.  Both require careful, detailed work.  So both are valuable, but each speaks to a different kind of written contribution to the evidence, and each requires a different skill set to produce and publish.  I do not think either indicates researcher ability, directly.  

In my opinion nothing aforementioned written separately is not indicated as a tool for researcher's judgement. May be review paper including own research will be useful as a tool.