I have been working in the recruitment industry for more than 6 years and I am familiar with all the job portals. But Wisdom Jobs has really impressed me with their unique features. They allow you to take unlimited number of skill tests for free and to display your test scores along with your profile. This can definitely give you an edge as recruiters like me are always trying to find better candidates.
They are also providing some study material for free. While this is not comprehensive, it is definitely helpful for you to brush up your knowledge before an interview. I myself am registered on Wisdomjobs.com, and I have suggested to my friends as well to register with them. I believe that this portal can really give jobseekers an edge with their unique concept.