The reason it's not at the top is that it's incredibly complex, and yet it's still about the most coherent description I've found of what really went wrong with the subprime market (and hence, the rest of everything else).

Outside of any individual, Lewis lays the blame for the crisis on two key factors: 1) the decision in the 1980s on Wall Street to take the investment banks public. With the shareholders essentially footing the bill, the employees lost all incentive to not be stupid. Had they been private and employee-owned, as they were before the 80's, Lewis believes that they wouldn't have taken such stupid risks so blindly.

2) Moody's and Standard & Poor, the two biggest rating firms, were asleep at the wheel. Again, they had no incentive to actually rate the subprime bonds accurately. They were, apparently, all afraid that they'd lose the business to the other guy. Plus, to a certain extent, they just didn't know any better. As such, billions of worthless loans were bundled as AAA rated bonds, essentially as good a Treasury Bills. Because they were rated Triple A, they escaped noticed of a lot of the banks upper management for years.

But forgetting all the financial stuff, the book's real enjoyment comes from following a group of about 6 people, few of whom who know each other, as they slowly begin to understand what's happening. As the book points out, some people saw it coming, but few were willing to stake their money on it. This book takes the subprime crisis through their eyes.

If that's interesting to you, and if you can wade through a couple dense pages every so often, I'd recommend the book.