I've always been a proponent of the Reality Lit approach -- the idea that you can get the most from an artist not by studying the artist's works in isolation but by looking at the artist's real life, almost as if the life and the works constitute a single continuous work. I guess this is why I originally designed LitKicks with such a strong focus on biography.
This approach can affect my view of a writer's work both positively and negatively (e.g., T. S. Eliot loses a few points for being an insufferable racialist and snob, but when I read about his sad struggles with his psychotic wife I give him a few points back). Often the life story adds an element that improves the whole -- Kafka is great no matter what, but the amusing irony that he earned a successful living as a middle-manager in an insurance company adds an edge that makes him even greater.
I know many people feel this approach is wrong -- that each work of art should be viewed in isolation. I understand that point of view, but that's not how I ever approached literature and I'm glad it's not. I guess I don't think any artist or any human being can have the talent to create the greatest masterpiece of all -- that bizarre and incomprehensible work known as reality.