This is what an INF(f?)P can do to an INTJ.No other type besides an INTJ has ever made me feel completely comfortable being who I most deeply and truly am. No other type has ever made me feel like my soul is being lifted, swung around, and catapulted towards the sky. I think one INTJ, either here or on the INFPg site, said this in reference to her relationship with an INFP: "We find ourselves stumbling into each other's souls quite accidentally and frequently." No other words were ever more perfect for describing the process of how I've gotten to know my closest INTJ babes.
They can be the most wise, intelligent and discerning of people, and juxtapose their extreme clarity of mind with, in the very next minute, the most endearing doubt. They can share their most deeply-felt desires and doubts with me and make me feel like we dipped our hands into the same cosmic, primordial pool at the beginning of time, because they are usually so similar to my most deeply-felt desires and questions.
They're romantics, idealists, and compassionate friends. They can be the silliest people and have the most childlike curiosity and sense of wonder, and then tackle the darkest, most controversial issues as though they're eating their daily bread (and I assume they probably are). Convention and tradition cower and wimper at the mere sight of INTJs, because under the keen eye of an INTJ they are rendered prostrate and powerless.
In addition to all that, of the four INTJs I consider pretty close friends, two of them in particular have particularly obvious, deep wellsprings of compassion. One of them drew me a picture of her taking my hand and flying us both into the night sky, and she put the lyrics to Savage Garden's "Crash and Burn" on it. ("If you jump, I'll break your fall, pick you up and fly away with you into the night. If you need to fall apart, I can mend a broken heart, if you need to crash and burn then crash and burn - you're not alone.") I remember how touching that level of caring was to me. She and I have weathered some storms together.
They are, hands down, my favorite type based on experience.