If you are focusing on the topic of characterization, I would have to pick stories that feature first person narrators who we come to suspect are unreliable. This is something that Poe does very very well in his fiction as he manages to create narrators that tell us their tale but whose sanity we doubt or begin to question through what they tell us and also through their actions. If you wish to explore this further, three great examples of this unique point of view are "The Tell-Tale Heart," "The Cask of Amontillado" and "The Black Cat." Each of these great tales feature a first person narrator who tries to come across as reasonable through what they say, but if you read the tale carefully and their account of what happens, you should be able to see that there is something strange about them as characters, and we begin to doubt the account they are telling us. Enjoy! These are all great stories! I have included links to the enotes study section for each one below. Good luck!