I read a ton of her books at a teenager and have since forgotten most of the plot details, lols.So, I recently listened to a bunch in a wonderful audio book - it's called 'Poirot's Finest Cases' and it's recordings of Full-Cast BBC Radio dramatisations of these 8 books:

• The ABC Murders
• After the Funeral
• Death on the Nile
• Peril at End House
• The Murder of Roger Ackroyd
• Murder on the Orient Express
• Three act Tragedy
• The Mysterious Affair at Styles

Highly recommend! There's a 2nd, 'More of Poirot's Finest Cases' with another 7 books. they're not as 'fine' as the first list, but I enjoyed Five Little Pigs, Evil Under the Sun and Halloween Party