Agatha Christie: She is the only one I have read. Here are all of her books that I know.
The ABC Murders
The Adventure of the Christmas Pudding
After the Funeral
And Then There Were None
Appointment with Death
At Bertram's Hotel
The Big Four
The Body in the Library
By the Pricking of my Thumbs
Cards on the Table
A Caribbean Mystery
Cat Among the Pigeons
The Clocks
Crooked House
Curtain: Poirot's Last Case
Dead Man's Folly
Death Comes At The End
Death in the Clouds
Death on the Nile
Destination Unknown
Double Sin and Other Stories
Dumb Witness
Elephants Can Remember
Endless Night
Evil Under the Sun
Five Little Pigs
4.50 from Paddington
The Golden Ball and Other Stories
Halloween Party
Hercules Poirot's Christmas
Hickory Dickory Death
The Hollow
The Hound of Death
The Labours of Hercules
The Listerdale Mystery
Lord Edgware Dies
The Man in the Brown Suit
The Mirror Crack'd from Side to Side
Miss Marple's Final Cases
The Mousetrap and Other Stories3 Blind Mice
The Moving Finger
Mrs. McGinty's Dead
The Murder in the Vicarage
Murder in Mesopotamia
Murder in the Mews
A Murder is Announced
Murder is Easy
The Murder of Roger Ackroyd
Murder on the Orient Express
The Mysterious Affair at Styles
The Mysterious Mr. Quin
The Mystery of the Blue Train
Nemesis
N or M?
One, Two, Buckle My Shoe
Ordeal by Innocence
The Pale Horse
Parker Pyne Investigates
Partners in Crime
Passenger to Frankfurt
Peril at End House
A Pocket Full of Rye
Poirot Investigates
Poirot's Early Cases
Postern of Fate
Problem at Pollensa Bay
The Regatta Mystery
Sad Cypress
The Secret Adversary
The Secret of Chimneys
The Seven Dials Mystery
The Sittaford Mystery
Sleeping Murder
Sparkling Cyanide
Taken at the Flood
They Came to Baghdad
They Do It With MirrorsMurder with Mirrors
Third Girl
The Thirteen Problems
Three-Act Tragedy
Towards Zero
The Underdog and Other Stories
Witness for the Prosecution and Other Stories
Why Didn't They Ask Evans
Here is a free ebook link for some of them:
http://allebooks4free.wordpress.com/2007/10/22/agatha-christie/
There you can find:
After the Funeral
And Then There Were None
Appointement with Death
Best Detective Stories
From Paddington
Nemesis
Secrets of Chimneys
The Moving Finger
The Murder at the Vicarage