Hermann Hesse, Siddhartha, 1922
This allegorical tale of a Brahmin's son who gives up everything in the search for his self is, in my opinion, one of the masterpieces of the 20th century. The story is short and clear, with one foot in Buddhism and another in Modernism. The first time I read this book (during one sitting in a Toronto cafe), I fell in love with it. Now, after reading it for the second time, I feel as if it will be the book I keep by my side, through out my life, for whenever I need to be comforted.
If you feel lost, depressed, unhappy or unsure about life in general, this book is worth a thousand self-help tomes injected into your blood.