Within the MBTI, the most objective type is ESTP, which are the four objective traits. The most subjective is its opposite, the INFP. The reason a P is subjective, is that the IP means the P is extraverted but internally the person is a J, which is subjective.
ESTPs accept things as they are, and let everyone know how they feel. INFPs see things in their own personal way and rarely if ever let anyone know, until they reach a level where they feel content with themselves, and then they teach the world. Until then, however, they just wonder why noone understands things as they see them (the INTP is the same way with logic judgements, except the INTPs being objective in their judgements are easier to understand, and thing people who don't understand are considered "stupid", unlike the INFPs who consider people morally incorrect).
INFPs can be wonderfully informative when sharing their own personal views with their well thought out values. However, some tend to be self-righteous and down right coercive, the best example of this (that i know of) being Kane from the Kung Fu shows in the 70s.
INFPs that grow up without an N as a parent tend to act like what their parents want to see or INTP until their twenties or so when they begin to have an identity crises and try to find themselves. Even when they do, they can be hard to spot, as they won't share their feelings with most people right away. I mistook one co-worker for an INTP once. After he notified me he tested as INFP, i came to a better appreciation of him.
Interestingly enough, it seems that most people (from my reading so far) on the MBTI has been INFP.