Modern Chess Openings, better known in the chess world as MCO, has been called "the chess player's bible" since it was first produced by Walter Korn almost 60 years ago.
It's hard to rate such a book since one must work through the openings one by one, but so far so good. The moves are listed clearly, the explantions and other text is well done.
A full chess openings book. Everything you want to study about chess openings you can find in it.
