I found this quiz on BrightDyes Blog.

You Are An INTJ

The Scientist You have a head for ideas - and you are good at improving systems. Logical and strategic, you prefer for everything in your life to be organized. You tend to be a bit skeptical. You're both critical of yourself and of others. Independent and stubborn, you tend to only befriend those who are a lot like you. In love, you are always striving to improve your relationship. You have strong ideas of what love should be like. At work, you excel in figuring out difficult tasks. People think of you as "the brain." You would make an excellent scientist, engineer, or programmer. How you see yourself: Reasonable, knowledgeable, and competent When other people don't get you, they see you as: Aloof, controlling, and insensitive

What's Your Personality Type?