The disturbing thing (from my liberal, British perspective) about the original D&D alignment system is that there were only three alignments (lawful, neutral and chaotic), and that Lawful alignment was understood to mean 'morally good' - or rather, that Lawful was defined the way you'd expect, and then stated to be morally good. This rattled me. I'd never encountered the idea of Law and Chaos as major issues before, and seeing the definitions didn't exactly make me believe the assertion about the moral value of the two extreme alignments.

In his book Role Playing Mastery, Gary Gygax asserts that AD&D's Lawful Good are the very best. This view is not consistently expressed in TSR or WotC publications, thankfully. It may be that the 'law=good' idea comes from growing up in a country where swearing an oath of allegiance to a flag is considered a good idea.