I've not read much Jack London before, thinking I wouldn't really care for him, but I was pleasantly surprised by this ebook from Project Gutenberg.

The life of Burning Daylight was quite a saga, from his 30th birthday, when he was already an "old-timer" in the Alaskan goldrush, to a life of high-finance in San Fransisco and even Wall Street. A varied, many faceted adventure and love story. Recommended!