I don't want to list a specific cert since the name of holders is public but GIAC certs (and SANS training) have been the most useful to me. They are very expen

I don't want to list a specific cert since the name of holders is public but GIAC certs (and SANS training) have been the most useful to me. They are very expensive and most people need a company to sponsor them as a result and also some in the industry complain about how them for one reason or the other but personally it isn't so much in terms of memorizing random facts or gaining some very deep insight but being exposed to very technical material and practical and current industry practices and knowledge. I think a lot of the critique is due to wrong expectations. You're not gonna become a threat intel expert or malware analyst because you took a sans/giac cert but it would be similar to taking a post-grad university course on the subject. They are also very vendor neutral and open source friendly. Their instructors are well recognized and accomplished in their respective fields. Security aside, CCNA has to be the most valuable IT certification. They are cisco specific but the sheer amount of knowledge you need to understand for it and the foot-in-the-door opportunity is extremely valuable. OSCP as well as others have noted.