A few years back I developed a comprehensive "grade card" to help me self-analyze my skills as a gamemaster and player with some degree of objectivity.
The criteria I selected was based on distilled advice from all over the web, and then refined down to a handful of core competencies that I feel are at the heart of being a good GM or player. (Yes, many of these are simple social graces. Roleplaying is primarily a social activity, and you can't succeed at it unless you are able to interact with others in a productive way.)
I'm sharing these forms with the gaming community in hopes that they will be useful, but with this disclaimer: These forms are meant as a constructive tool for self-improvement. They are not meant to demean anyone or to be used as ammunition for arguments. You can use them to rate yourself (be as honest as you can), or if you're thick-skinned, give copies to your gaming group, ask them to rate you, and compare the results.
The forms are available here. Enjoy!