Going Postal, and its sequel, Making Money, remain amongst my absolute favourite Discworld books. Why? I think one of the things that I enjoy about Moist von Lipwig is that he is great at improvising and succeeding with his improvised plans. I love characters who do that, like the Doctor, or Miles Vorkosigan. And yes, I do understand that he needed a moral comeuppance. Otherwise, he would have kept ignoring the consequences of his actions, or at least those not directly pertaining to him. At least he was honest enough (irony, much?) to divulge what he did to Adora in the end.