The Maltese Falcon by Dashiell Hammett is, in many ways, is the beginning of the archetype of the hard boiled pulp Noir detective. Sam Spade and Philip Marlowe together are pretty much IT, and the film adaptation of the book is nothing short of a classic. Besides, nobody comes close to Bogey! Check out these ten clips from the flick. You can even watch the whole thing on YouTube for only like 3 bucks!
And here's the whole film rental:
Troll Lord Notation: This is one of the best movies I've ever seen.