What produces extraordinarily good people?

Start with some extraordinarily good parents, or advisors, or mentors. Very few of the good people create their extraordinarily good moral codes ex nihilo.

Next it helps to throw in a society that holds that essentially good behavior is based on similarly good principles. If your society promotes rotten behavior, if your society holds that it's really clever to cheat your neighbor or that the winner is the one who made off with the greatest amount of stuff, you're going to produce a lot of rotten apples with very very few extraordinarily good people.