On a recent Donald Miller's blog he discuses the Enneagram. The Enneagram is a personality assessment tool, but it differs from others assessments because it doesn’t seek to tell who a person is, but rather, how a person hides who they are. There are nine personalities on the Enneagram.
I've always been fascinated by these types of test ever since I took my first one, the Myers-Briggs (which according to I'm an ISTJ), over 15 years ago. The results are always very enlightening and usually dead on. Here is the results from my Enneagram test that Donald discusses:
Type One: The Reformer (Which as you can see in the above diagram also reaffirms my ISTJ assessment from Myers-Briggs)
The principled, idealistic type. Ones are conscientious and ethical, with a strong sense of right and wrong. They are teachers, crusaders, and advocates for change: always striving to improve things, but afraid of making a mistake. Well-organized, orderly,and fastidious, they try to maintain high standards, but can slip into being critical and perfectionistic. They typically have problems with resentment and impatience. At their Best: wise, discerning,realistic, and noble. Can be morally heroic.