My all time favorite is J. R. R. Tolkien's "The Hobbit" and "The Lord of the Rings"!
Georgette Heyer -- Regency Romances
Daphne Du Maurier -- Rebecca, My Cousin Rachel, Jamaica Inn, The House on the Strand
R. F. Delderfield -- Swann saga: God is an Englishman, Theirs was the Kingdom, Give us this Day.
Dorothy L. Sayers - Lord Peter Wimsey Mysteries
Agatha Christie - Poirot Mysteries; Miss Marple Mysteries; Tommy & Tuppence Mysteries
Sir Arthur Conan Doyle - Sherlock Holmes Mysteries
Rex Stout - Nero Wolf Mysteries
Ngaio Marsh - Inspector Roderick Alleyn, gentleman detective mysteries.
Edgar Allan Poe - The Murders in the Rue Morgue; The Raven; The Cask of Amontillado; The Pit and the Pendulum, The Purloined Letter, The Tell-Tale Heart,
C. S. Lewis -- Chronicles of Narnia
Mary Norton -- The Borrowers, The Borrowers Afield, The Borrowers Afloat, The Borrowers Aloft.