Totally subjective. What makes one story (or poem, or short story, or...) 'better' than another in your opinion? Or, think of it this way: what is it about your favourite book / poem / etc that makes it your favourite? What has to be included in the piece to make it a good piece to you? (In most cases that is; we all know about the book with the killer plot that makes it awesome even though the characters are flat and stoic.) Assuming we're all looking to get published one day, or at least entertain whoever reads our work, I think it's important to listen to potential readers; listen to them when they tell us what they want to read. For me, I think it's all about the character. You can have an amazing plot, but if your character is dull and uninteresting, I'm going to put down the book. Story is what happens to people, after all. In addition, the writer has got to have some sort of recognizable voice. Whether it's sarcastic, funny, charming, or even rude, I dont want to feel like I'm reading a textbook.