I'm not on your list of choices: xNTJ.
True "x" - I can walk into a room and comfortably strike up a conversation with a stranger and I'm perfectly happy spending long periods of time alone. Been tested enough times and I straddle the I/X line.
I'm the same way, but xNTP. Always test E but I know there is a huge amount of I in there, too. I can chat anybody up and I do truly enjoy being with people (who are not assholes) ... But I also love being alone with my thoughts and after a certain amount of time with people around, I start to get drained and/or bitchy. It's better for everyone if I get plenty of unstructured alone time. :)
For years I tested as F instead of T, but I think that was largely due to being a woman. We are so thoroughly conditioned to be feeling that I just became fluent with my feelings by default, but fundamentally I think I really am a T, and as I get older that expresses itself more strongly.
(In fact, I believe that I was able to gain whatever emotional/social fluency I have through the power of T. As a child I think I may have been mildly on the autism spectrum, but about age 18 I decided to apply my brain to learning how to act with people by observing them. Pure T...)
Honestly I feel like I'm pretty close to the line on all of the axes -- lots of times when I take the tests have a hard time choosing answers because I could easily choose either depending on the context. So I'm not sure how accurate any of t is, but like the horoscope, it's kind of fun to think about.