INTJ on two occasions and INTP on one. I test more as INTJ in work situations and INTP once during my short interest in history.
"For a man who wants to make a profession of good in all regards must come to ruin among so many who are not good. Hence it is necessary to a prince, if he wants to maintain himself, to learn to be able not to be good, and to use this and not use it according to necessity."
First time I tested, I came out as ISFJ, but I became aware that I hadn't really understood Keirsey's questions. The description didn't describe me too well. After that, I always came out as INFJ. Once INTJ, but I don't think that test was very reliable.