If we take the textbook definition of intelligence, there is no doubt Id have to rate myself a ten. The majority of people here would have to do so. As the above table shows, you dont have to be an insane super genius to be in the tenth percentile of intelligence. Everybody with a CS or other STEM degree almost certainly is. Again, that is, assuming your ten point scale linearly maps to the textbook definition of intelligence. But you seem to be asking for a more subjective impression.
But by any subjective standard, id also rate myself a ten. I have my shortcomings, as does everybody, but the number of people I know who really inspire me as being a better person than myself, in the sense that the thought of trading places with them wouldnt be utterly laughable; I can count them on my fingers (the number of people who have one or more traits that I envy is considerably larger, but im talking averages). No way that id trade places with one in ten people I know; which is a group of people already highly selected for perceived awesomeness. Perhaps that is indeed more a measure of arrogance than anything else, but there you have it. 10/10.
I rated myself a 10 as i'd guess most responders should have. Whom here isn't in the top 10% of demonstrable intelligence? Simple self selection would dictate that an honest assessment would have a heavily weighted upper end given the context of the site.
Some faux-modest wankery is the likely culprit that is imitating [font="helvetica, arial, verdana, tahoma, sans-serif"][color="#282828"]