Almost an impossible question to answer, in my opinion.
There are sub-genres within the genre.
My first experience with the detection stories was Sherlock Holmes, the short stories were the subject for study in one year in my grammar school. I enjoyed them so much I used to get up early to read them before going off to school.
My elder sister was a big Agatha Christie fan and I used to read her books when she had finished with them (I remember reading one in one sitting, think it was WHY DIDN'T THEY ASK EVANS}. I thought Poirot was a wonderful character.
I then moved on to authors such as Alastair MacLean, I thought THE GUNS OF NAVARONE was an excellent book at the time and is one of the few books in this genre that I have re-read.
Now I like to read police procedurals, courtroom thrillers, political conspiracy type books.
Tastes change and a book you once thought highly of, if re-read now might diaappoint.