I love this movie. I didn't love it until I'd watched it a couple of times.
And I didn't love it quite so much until I'd read Harvey Greenberg's "Movies on Your Mind."
But I now think that, within the strictures of its budget, it's about as good as it can get. Sam Spade is a marvelous character in this film. He gives practically nothing away, while gathering information from others simply by letting them talk, kind of like a shrink.
And it's hard to believe that they could have found a cast that fit the templates of the novel so perfectly. Sidney Greenstreet IS the "fat man." Peter Lorre IS the queer. My nomination for best scene: When Greenstreet attempts to peel off the black enamel from the captured bird and finds that it's nothing but lead and begins to hack away at it, as if it were alive and he were trying to kill it. Nothing is more amusing than a fat man lipid with rage.
If you see this one, and I hope you do, make note of the phenomenal black and white photography. (I hope you have a good connection.) Watch, for instance, the glissade of the camera when Bogart says, "You have brains. Yes, you do."
In case you're worried about this being too sophisticated for enjoyment by an ordinary audience, I should mention that I showed this (in one connection or another, I forget) to a class of Marines at Camp Lejeune. They enjoyed the hell out of it, especially the scene in which Mary Astor kicks Peter Lorre in the shins.
Don't miss it.