I didn't read through this complete thread but most of it and I didn't see anyone suggest one of my favorite American Classics: To Kill a Mockingbird
is a novel by Harper Lee published in 1960.
I love this book and have read it several times. Please forgive if it has already been suggested.
I also have enjoyed Mark Twains several short stories written by Mark Twain.The Call of the Wild
by Jack London
When his beloved master is killed, the dog Buck flees to the wild, where he becomes the leader of a wolf pack. Rousing adventure set in Alaska’s Klondike country.Lord of the Flies
by William Golding
A group of English schoolboys, marooned on a tropical island during a time of atomic warfare, bring both civilization and savagery to their community.
These are a few additional classics I like.
I am a huge suspense, thriller fan and would recommend some of Ken Follett books especially some of his earlier ones Eye of the Needle
It is 1944 and weeks before D-Day. The Allies are disguising their invasion plans with a phoney armada of ships and planes. Their plan would be scuppered if an enemy agent found out... and then, Hitler's prize agent, “The Needle”, does just that. Hunted by MI5, he leads a murderous trail across Britain to a waiting U-Boat. But he hasn't planned for a storm-battered island, and the remarkable young woman who lives there.The Key to Rebecca
North Africa in the summer of 1942 and Rommel seems unbeatable. His secret weapon is Alex Wolff, master spy, and a deadly code buried in the pages of du Maurier's novel, Rebecca. Crossing the blazing Sahara, Wolff enters Cairo to steal British military plans. His pursuer, Major Vandam, engages the lovely Elene to lure him into range. As Rommel's troops come closer to victory, the pursuit continues across the desert to a startling, explosive confrontation.The Man from St Petersburg
In 1914, Germany arms for war and the allies are preparing their defences. Both sides need Russia. The Earl of Walden and Winston Churchill plan a secret Russian alliance, but a man steals into England, intent on leaving his mark on history. Fate catches up with a beautiful woman, a young girl and a star-crossed lover, while the police close in on the man who might bring England to her knees.
I hope I have hit on a few books you haven't read yet.