A good argument, to me is one in which all parties involved, do not raise their voice and share only truthful and accurate information and experiences, and allow each other equal time to express their views. Why, because it has been my experiences that everyone learns from this kind of argument. Now if you are referring to argument in the form of a point you are trying to make, what makes a good argument is this situation is when you know that you have something valuable to share with others and you have done all your homework on the subject, this makes a good argument.