I got ENTJ on one and INTJ on two others. On the extraversion/intraversion spectrum, I scored so near the median, it’s safe to say that part of it is irrelevant to me. So I’m really just an NTJ.

As it turns out, it was all spot on.

“To outsiders, INTJs may appear to project an aura of “definiteness”, of self-confidence. This self-confidence is sometimes mistaken for simple arrogance by the less decisive.”

“INTJs know what they know, and perhaps still more importantly, they know what they don’t know.” 

“INTJs are perfectionists, with a seemingly endless capacity for improving upon anything that takes their interest. What prevents them from becoming chronically bogged down in this pursuit of perfection is the pragmatism so characteristic of the type: INTJs apply (often ruthlessly) the criterion “Does it work?” to everything from their own research efforts to the prevailing social norms. This in turn produces an unusual independence of mind, freeing the INTJ from the constraints of authority, convention, or sentiment for its own sake.”

“INTJs really want people to make sense.”

“When challenged, the ENTJ may by reflex become argumentative. Alternatively (s)he may unleash an icy gaze that serves notice: the ENTJ is not one to be trifled with.”

If you’d like to find out your own personality type, I took these tests: 
http://bloginality.love-productions.com/,
http://www.humanmetrics.com/cgi-win/JTypes2.asp,
and another that I can’t seem to find now.