I find I best enjoy the stories that don't feature Poirot or Marple, the stories in which ordinary people find themselves ensconced within the mysteries. Examples: The Man in the Brown Suit, The Pale Horse, The Secret Adversary, Sparkling Cyanide. Some of these feel even more like thrillers than general mysteries, and they tend to be more absorbing and compelling than the others.
I don't know if there's a way of referring to these books to distinguish them from the Poirot/Marple series, but I wonder if you guys could give me some more titles so that I can find them more easily? I'm not trying to avoid the others---I like them too---I'd just like to have the titles in mind so I can readily identify them when I'm browsing the library catalog.