It seems that almost every compilation book or convention pack I read has a diagram by Stephan Weber in it. This is his personal website, and there is a nice gallery of his work, from classic to recent.
This Korean blog highlights some impressively complex models. Unfortunately, I'm not sure who the creator is, and I really wish he would fold these models out of some decent paper. And also photograph them in front of a neutral background, instead of his desk or bookcase.
This site has some superb models on display. Many of the human figures demonstrate box-pleating at its most gonzo, and it is difficult not to be amazed by the complexity. Be prepared to spend hours figuring out how Takashi Hojyo does it.