That especially clear light that Luther shed upon the Scriptures, Law and Gospel, is a proverbially tough nut to crack. One of the first inter-Lutheran dust ups was on this topic under the name of Antinomianism. Ever since, “antinomian” has been a favorite epithet among Lutherans debating one another. As an epithet, it is widely and imprecisely used. So let's aim at some more precision.
Hard Core Antinomianism: The moral law simply does not apply to Christians. You may do whatever you find desirous – indeed, to indulge in acts that are contrary to the moral law may be encouraged because it helps get it out of your flesh's system. This is Münzer and almost nobody else.
Agricolan Antinomianism: The classic brand. Christians do not need to hear the preaching of the Law because the Gospel alone will bring about good works. This is refuted in FC VI.
Once Saved, Always Saved Antinomianism: A Christian does not lose his faith even if he engages in open, willful, persistent sin. Luther seems to have imputed this idea to the Agricolans, but maybe that wasn't quite fair. At any rate, he vociferously attacks this version of Antinomianism in SA III.3.42-45.
Liturgical Antinomianism: Binding, enforced regulations regarding the worship life of the Church are incompatible with the Gospel. The COP's theses on worship released some months ago tread awfully close to this error – it is refuted in AC XXVIII.
Moral Law Antinomianism. Someone who denies part of the moral law is rightly called an Antinomian. However, the title is usually tossed about in a way that casts all heat and no light due to the fact that it is almost always used as a form of begging the question. For example, let us imagine two men and name them...oh, I don't know.... “Luther” and “Rehwinkel.” Luther says contraception is a sin, Rehwinkel says it isn't. Luther calls Rehwinkel an Antinomian; Rehwinkel calls Luther a Binder of Consciences. Both of those statements are begging the question. The debate is whether or not contraception is a sin. If it is, then Luther's no Binder of Consciences. If it is isn't, then Rehwinkel is no Antinomian. So just calling someone with whom you disagree over a particular point of moral law an Antinomian is really just a fancy way of restating your position without arguing for it: that is, question begging, petitio principii. Now, it is certainly true that Lutherans who accept homosexual acts as A-OK are rightly called Antinomians – it's just that saying so in the midst of an argument with them is not an argument, but just a statement of one's position.
Are there any that I missed?