Book recommendations?

I'm taking a Detective Fiction class, and for an upcoming project we're supposed to do a study of "a contemporary (post-1940) writer of detective fiction, or a trend or theme emerging during that period." I thought I had the perfect series picked out, until the professor told me I had to choose something I hadn't already read.

So I'm looking for recommendations for post-1940 detective fiction, preferably by authors who have written at least two or three books. Anyone have any suggestions?

How have you read?

I sugest you go to http://awards.omnimystery.com/mystery-awards.html and review who has been nominated for the specific mystery award.

People will probably disagree with me, but I feel a post 40s trend is the use of place as a character.

Two examples (British ones, I'm afraid) Ian Rankin uses Edinburgh in his Rebus series - explained further here: http://www.ianrankin.net/pages/content/index.asp?PageID=146

Mark Billingham uses London in all but one of his DI Thorne series.

There's a few papers on the subject here: http://www.dartmouth.edu/~gjdemko/defining_place.htm

and

http://jsydneyjones.wordpress.com/2011/04/24/the-crime-novels-of-jim-kelly-the-cold-bleak-landscape-of-the-fens-seems-to-seep-through-the-paper/

as above, with the American southwest of Tony Hillerman and New Orleans for James Lee Burke. The books aren't just 'set' there - these places completely define all the other characters in their books and the authors was poetic on the geography as much as on the human inhabitants - indeed, it's often the geography that motivates/conspires against/propels the action.