This book is the best collection of Nietzsche's writings. Kaufmann's translation is incomparable; it has energy, wit; its language is a delight. In other translations Nietzsche comes off as much more ponderous.
The Birth of Tragedy is a good place to start for knowledge of the early Nietzsche and is an indispensible book for understanding what came later. The Genelogy of Morals is the least aphoristic of Nietzsche's writings and provides an extended treatment of Nietzsche's famous and infamous views on morality, especially Christian morality. Beyond Good and Evil is aphoristic brilliance containing many of Nietzsche's most famous ideas.
The one thing that would make this book perfect is the addition of Kaufmann's translation of the Gay Science.
For those interested in Nietzsche there is no better place to start than this book.
Nietzsche like Plato and unlike most philosophers really knew how to write. His writing is brilliant, original, and his style has no peer. Kaufmann produces English that is without peer in his translation of Nietzsche's works.
Whether you love him or hate him, exposure to Nietzsche can be a life-changing experience.