r102, I was, like a duckling, firmly imprinted with AC as a young teen, after viewing the Tyrone Power "Witness For the Prosecution." That started an obsessive hunt, long before she was a gleam in the eye of PBS, for every Christie work, with a few side excursions (Dorothy L. Sayers, Jonathan Gash, Erle Stanley Gardner, Mike Hammer) that, alas, have yet to include Chandler.
But as for SERIOUS Classics, I would highly recommend "Wuthering Heights" for not only its brilliance of characterizations, its wildness of setting, and its uniqueness of plot, but for its imagery: dogs; dreams; windows; and I forget what all. The depth and emotion of this novel is staggering.
The last is true also of the great "Madame Bovary." When taught this, I learned about its style and circular structure, elements that set a Classic above "a good read."
Of all the novels in all the world, I find these two most essential. I know; I know; "Moby Dick," "Crime and Punishment" (read and wrote a book report of in Grade 9), "Don Quixote," etc. I'm just sayin' for me.
You know what I love most about Guy de Maupassant, r101? Saying his name! "Ghee de Moepuhsont"!
R103, Were you in my Comp Lit course in 1970?! I didn't expect to see the names Mishima ("The Sound of Waves") and Hesse ("Steppenwolf") mentioned!
As for American writers of Classic works, my favorites are Hawthorne, Hemingway, and Steinbeck. I focused on Sinclair Lewis for Grade 11 book reports, but have never looked back, haha.
Were I to be young and beginning my studies, I would read more source material: "The Song of Roland"; the "Epic of Gilgamesh"; indeed, the Bible.
Luckily for me, I had been a Greek and Roman mythology freak from childhood (Hello, Edith Hamilton!), so Joseph Campbell, Heston, and Ovid were natural follow-ups.
Of course, above the entire pantheon sits, as r135 put it, The Man: Shakespeare (or "Shakespeare"). He understood the Human Condition sans peer.
But I would insist that to really understand the Classics, one needs a grounding in sources, in mythologies, folktales, artistic movements, symbolism, the social milieux.
This necessary underpinning of knowledge is why one might see child prodigies in music, child prodigies in mathematics, child prodigies in chess---but never child prodigies in true literature.