Anton Chigurh is to me a True Neutral. Laws and morality do not matter to him, which strip him of both lawful and good. He's not irrational, illogical, nor born of passion, which strips him of chaotic. As far as evil is concerned he never did anything blatantly evil that was without purpose. He killed only those who he was paid to kill or those who threatened his mission. As he said when he whacked the wife at the end, the husband made the choice to gamble with her life and lost, and he gave her the opportunity to gamble and win it back, so the motive wasn't born of malice or hatred. She refused to take her chance to change her outcome and so the previous outcome stood.