Personality types

Sometimes differences are immediately apparent, and sometimes they take time to manifest.
My ex and I were (are) polar opposites and you don't have to know either of us to see it-- just stand us side-by-side and you'd see. She's a butch-jock-tommy hilfiger wearing, SUV-driving, snowmobile-riding, poker-playing, hard-partying real estate broker/salesperson. I wear whatever was on top on the mound in my closet, most likely ripped jeans and a tank top or sweatshirt depending on the season. I am rumpled and unkempt. I prefer trees to SUVs, coffee to beer. My favorite thing about snow is the quiet it brings with it. I might go to a party if I can't think of a good enough excuse to get out of it, but I prefer nights in with gf or a few friends, netflix and scrabble over beer pong and pool. My profession is thinking, analyzing, writing-- 95% of it is in my head. I can go for days without interacting with anyone in my office, much less anyone outside it. My introversion can go to extremes. Sometimes I can verge on agoraphobic and anxious. Sometimes my dislike of interacting with people can become problematic, like when I refuse to call a restaurant to order in because I can't bear the thought of talking to a stranger.
But when gf and I got together I was overawed by how much we had in common; we liked the same things, thought the same thoughts at the same time, had similar predilections for gloom and sarcasm lightened with lewd humor.
As we have gotten to know each other, though, very clear back-end differences have emerged. I'm a planner, a pragmatist, a problem-solver. I am slow to anger but also hard to appease once angered. Gf is fluid, mercurial, manic, unpredictable and changeable. Plans to her are not so much plans as aspirations, given to change at the last moment, or with the next mood. She is emotional and reactive. I am logical and phlegmatic. We do well with these differences, give each other balance in ways that we both need.
It was no surprise then, when we took the Myers-Briggs personality test (a quick and dirty version is here) and fund that we were polar opposites: as opposite as they come.
M/B ranks you on four dimensions:

Introverted/extroverted (I/E)
Intuitive/sensing (N/S)
Thinking/feeling (T/F)
Perceiving/Judging (P/J)
(for more detail, here's a cheat sheet.)

It might come as no surprise to anyone that I am introverted, sensing, thinking and judging-- the most rigid of all types; gf is ENFP, the most fluid. What are you?