Kurt Vonnegut: I want to share with you something I’ve learned. 
Why chart the emotions of the protagonist to evaluate the story? The value of a story is not in how happy or sad the protagonist was - but how it makes you feel.<p>If I had to evaluate stories, my vertical axis would have 4 parts.  From top to bottom:<p>* Unpredictable and irrational<p>* Surprisingly Unpredictable<p>* Tolerantly Predictable<p>* Predictable and stale<p>The closer the story is to "Surprisingly unpredictable" the better it is.<p>Cinderella, Kafka, Hamlet - all reach that point.<p>(But to be fair - Cinderella reaches that point only because its amongst the first few stories you ever hear.)<p>Titanic reached that stage for many teenage girls by killing the hero.<p>The best book I've read - Foundation Trilogy by Isaac Asimov reaches that "surprisingly unpredictable" point too.