I had read some of Eliezer's writings on Overcoming Bias back while he was still constructing the sequences, but I'm pretty sure it was reading Lost Purposes that got me gripped enough to want to go on and read the entirety of the sequences. It's possible that other articles I encountered in the process were better written, but that one remains more memorable.
However useful the content, what are some examples of the best nonfiction writing on Less Wrong? Are there pieces you think are as good as recent classics of essay form like I Think You're Fat or Lies We Tell Kids? For example, I like Yvain's The Apologist and the Revolutionary.
Which pieces would you nominate as some of the best nonfiction writing on Less Wrong?