Depending what you're looking for, Greene and Canary are fairly classic mysteries, Bishop has a cool premise and setup that gets lost in the middle/end (in my view that is)...

... and Dragon is HILARIOUSLY silly crack. Maybe the most memorable concept I've encountered in the Golden Age genre and I almost want to see it filmed just for some of the window dressing. I've spent a fair amount of time racking my brain for other detective fiction related to/inspired by/inspiring it, but I haven't even really come up with anything yet.