everything that suggests that the book is meant to drill the "correct" ideas into your head, rather than teach you how to develop good thinking practices on your own, is a no-no.
So how about:
Mysterious Answers To Mysterious Questions: Everything You Never Knew You Wanted To Know, About Things Most People Never Even Question
500 Mindbending Daily Essays on Truth, Beauty, Science, Reasoning, Intelligence, Bias, Optimization, Wisdom, and Ethics, And How You, Yes YOU, Can Become Smarter, Stronger-willed, And Maybe, Just Maybe Save The World
(Replacing the "500" with an appropriate number, of course.)
Quantum Computing Since Democritus got me thinking that we may want a more riveting title for The Sequences, 2006-2009 ebook we're preparing for release (like the FtIE ebook). Maybe it could be something like [Really Catchy Title]: The Less Wrong Sequences, 2006-2009.
The reason for "2006–2009" is that Highly Advanced Epistemology 101 for Beginners will be its own ebook, and future Yudkowskian LW sequences (if there are any) won't be included either.
Example options: