I first read Guy De Maupassant in junior high school (I can't remember what grade). The story was called 'The Necklace'. I never forgot the author or the story. It is a true masterpiece and for a short story covers a very broad range of human behaviors. Guy's stories in the collection that I am currently reading have perhaps less of an element of surprise than The Necklace. Also, they are of a very different style than Saki's stories, in which you can almost always expect a twist at the end.
To me Guy De Maupassant's stories like 'Boule de Suif' and 'Two Friends' are an intellectual challenge to the prevalent norms of the age in which they were written. These tales cover ideas like society's bigotry in defining virtue, and the injustice of war, respectively. Best of all they insinuate one to think and decide for oneself. Truly outstanding literature.