N is absolutely positively the most important to me, though I feel guilty I didn't pick F. I guess I'm not nice enough a person.:wink:
I test as almost 100% N, and I will look at an S and not understand how they live (no offense, yall). It seems like a shallow life (not shallow as in superficial, but shallow as in living on the surface of things), while N is so rich and imaginative and meaningful and wonderful in a way words cannot describe. I am filled with love for N. Even Ns with more S than me seem shallow sometimes. (I just realized I'm describing my N in a very feeler-type way. Don't worry F! You're my second favorite!)
With I and P - well, I would love to be more extraverted and I end up 'pretending' to be J a lot of the time anyways, so I don't care as much about them. I actually think it would be fun to be ENFJ. (I was thinking about other types I'd like to try, and I realized that I wouldn't like to be anything other than NF. I love them so!)
I'm thinking about it even more, and I like the lifestyle that P defines. Always on the edge, feeling your way down the hallway of life - it seems just a better way to live than planning every step of the way. So my least important letter to me would be I.
Oh, and I think that previous people are right that our dominant letter = most important to us.