Share 'So, I'm teaching a "Mystery As Lit" course next semester. What books should I use?'

I'm going with Mosley's "Devil In A Blue Dress" for sure. Also something by Chandler, but which one? They're all so great, but is one particularly iconic or complex? I'd like to teach one of van de Wetering's books, and probably an Agatha Christie. So I still need three or four more. Any suggestions/thoughts would be most helpful. Diversity/variety is a big plus.