Finding the model short story that appeals to everyone isn't easy. Every reader has different tastes in writing styles and genres. What I consider a model short story, might not appeal to that guy standing over there in the corner and vice versa. But over at The Literarian they've attempted to point readers in the direction of what a few writers consider the model short story. You can read them here.
One story that I like to use as a model for my own writing is "A Jury of Her Peers" by Susan Glaspell. It was written in 1917 so many find it hard reading, but I like the way it's laid out. You aren't told the straight up story of the murder that's taken place, you see it unfold through the eyes of the murderer's friends.
And while we're looking at model stories, feel free to add yours in the comments. It's always fun to share stories.