Harry Potter and the Methods of Rationality

Yudkowsky has written one of the best possible fan fics. In fact, his handling of Harry Potter is so good that his book has actually replaced the real thing in my head as my idea of who Potter and all the other characters are. What started out as a devise for conveying instruction on the methods of rationality rather quickly turned into a ripping good story that hung together in a most satisfying way.

I took four years to read it, which I do not recommend. Get to the ending with the middle of the book still fresh in mind – that will serve the reader much better.