Also, Sons and Lovers, D. H. Lawrence, has a couple of death scenes- one of the children and the evil possessive mom who gets an overdose of morphine.
The novella Bicentennial Man I think focuses on the main character "decaying" and dying like a human.
The Master and Margarita by Mikhail Bulgakov starts with a character being decapitated by a tram car and follows his last thoughts.
If I remember correctly, Surely You're Joking, Mr. Feynman has a description of Feynman's wife and her last hours. I don't know if you are interested in non-fiction.
Catch 22 by Joseph Heller.
All Quiet on the Western Front. Other war books, probably.
If you are desperate, newage books on Near-Death Experiences. Vampire novels where people "die" and are reborn as bloodsuckers.
I can't say how many books as a percentage describe the exact moment of death. It may depend on the point of view you are looking for. Is it the guy dying or another observer? Maybe it also depends on the genre you are reading. Maybe some authors like it better than others (Steinbeck now comes to mind, actually).