This protagonist, the iconic Philip Marlowe--along with Dashiell Hammett's Sam Spade--served as the prototype for all the hard-nosed, smart-assed, heavy drinking, distrustful private dicks that followed. Through the first-person eyes of Marlowe, the reader sees the seedy side of Los Angeles of yesteryear as told in increasingly more unique and inventive simile, rich with fascinating imagery. Marlowe's world view is sardonic and disillusioned, which whether intended or not traverses the decades that have passed and remains strikingly relevant today.
Perhaps that is the most impressive aspect of the book as a whole. Aside from a detail here and a rare bit of arcane dialogue, The Big Sleep never feels even remotely antiquated. Philip Marlowe could just as easily have been bouncing around the Los Angeles underworld today. More importantly, it seems as though if it were published today The Big Sleep would be a huge smash hit. To be able to say something like that about a book published 73 years ago speaks not only to its staying power but also its vision. Its brilliance is self-evident from the moment the book kicks off to its thrilling conclusion. If for one reason or another you've not read Raymond Chandler, do yourself a favor and pick this up.