I wrote the following for a piece on onscreen chemistry for MSNBC. I began talking about comic opposites and then landed here:

The genre where on-screen chemistry doesn’t require opposites is drama. Humphrey Bogart and Lauren Bacall, despite obvious differences (and viva those), sizzled in “To Have and Have Not,” in part, because her character, Slim, was as cool as Bogart, which is saying a lot. She plays a pickpocket who uses her sexual allure to separate men from their money. At one point she lands in his lap and kisses him, where we get this exchange before the more-famous exchange about whistling:

Bogart (smiling): What'd you do that for?
Bacall: Been wondering whether I'd like it.
Bogart: What's the decision?
Bacall: I don't know yet.
(She kisses him again; he kisses back; she stands up and smiles.)
Bacall: It's even better when you help.

This may be the coolest woman ever to appear in movies ...

Haven't changed my mind on that. Here's the New York Times obit. Nathaniel Rogers counts down her 10 essential roles. 

“It's even better when you help.”