Matrix tricks [by Puntanen, Styan, & Isolato]
While I have not read it but only browsed through, the book Matrix Tricks for Linear Statistical Models: Our Personal Top Twenty by Simo Puntanen, George P. H. Styan and Jarkko Isotalo, sounds like a very enjoyable book! Containing not only tricks, but also stories, pictures, and even stamps! Simo is the current editor of the book review section of the International Statistical Review, who is handling with much benevolence my book reviews, while George was for many years the fantastic editor of the IMS Bulletin. (Just to warn the readership I may be slightly biased in my evaluation!)