There are few people in the world as extraordinarily brilliant, yet practical as Charlie Munger, Warren Buffett's right hand man at Berkshire Hathaway (brk.b). In reading everything I can find on him I have significantly improved my own mental models, but there just aren't many Charlie Munger's out there. This is a gem of a speech regarding the causes and behaviors of the Financial Crisis. It is about 10 pages but I assure you that you won't regret having taken the time.
Disclosure: I am long BRK.B.