The Intelligent Investor
by Benjamin Graham
First published in 1949, this investment classic has sold millions of copies and is the bible for many value investors.
A quantitative investor at heart, Graham believed that all the qualitative aspects of a company would manifest themselves in the financial statements. By understanding the statements and trends therein, Graham could correctly assess a company's prospects.
The first 10 chapters cover investment basics like investing vs. speculation, stocks vs. bonds, inflation, advisers, "defensive" vs. "enterprising" investing and margin of safety. The last 10 chapters focus on securities analysis for the lay investor and include topics like financial statement analysis, per share earnings and assessing management. Lots of examples are used, and while some may be a bit dated, the key points are driven home. Warren Buffett calls it one of the best investment books ever written.