There are a couple of exceptions, of course. OSCP is a good certificate to have. To pass the exam, you are required to not only demonstrate proficiency in several areas (i.e SQL injection, buffer overflows), but you must also write and submit a technical report to a review team. The technical report must address vulnerability overview, impact, risk rating, reproduction steps, and more. Of course the exam isn't perfect, but it's probably the biggest test of real technical understanding and ability I've ever seen.