Poirot was the master, Marple was the apprentice and Tommy & Tuppence are good amateurs. But these Agatha Christie mysteries are stand-alone novels that aren't part of those franchises, and are listed chronologically. How much of the queen of mystery have you read?
If you're an Agatha Christie fan, you can see other challenges and lists at the lists below, concluding with the ultimate Agatha Christie Challenge:
The Agatha Christie & Hercule Poirot Challenge:
https://www.listchallenges.com/the-agatha-christie-and-hercule-poirot-challenge
The Agatha Christie & Miss Marple Challenge:
https://www.listchallenges.com/the-agatha-christie-and-miss-marple-challenge
The Agatha Christie and Tommy & Tuppence Challenge:
https://www.listchallenges.com/the-agatha-christie-and-tommy-and-tuppence
The Ultimate Agatha Christie Challenge:
https://www.listchallenges.com/the-ultimate-agatha-christie-challenge
