Compendium of Theoretical Physics (ISBN 0387257993)

Excellent Compendium:
This is the best compendium of theoretical physics I could find. It is NOT meant to be a text book. It is merely an organized collection of important results accompanied by brief derivations (when required). It is a great book for someone who does not want to see the full derivations. Also, if one works out all the results/example applications in the book, that person would gain a lot in terms of both problem solving skills and physical understanding by the end of the exercise. It is a compact book, so not very hard to carry around. It would have been nicer if the authors spent more time on general relativity but one must not be greedy :)