Covenant, Dispensationalism, and New Covenant Theology

I have been reading lately about the differences between all three of these systems. As far as my personal leanings, I seem to lean more towards NCT. This is because as the Apostle Paul has written the law has been fulfilled in Jesus Christ. Thus, dividing up the Law into 3 different categories seems to disregard this verse of scripture. Let it be known, that I do believe the Law can and should be used to show the sinner his helplessness before our Holy God. Nevertheless, the law of Christ takes affect with the believer once he/she has become a Christian.