How lenient are you when...?

... a book isn't necessarily the best written work, but it has a powerful and engaging message (examples might be "1984", "A Clockwork Orange", or "A Scanner Darkly")? Do you prefer those over works that are very well written, but their message doesn't necessarily pack as big of a punch (examples could be "East of Eden", "The Great Gatsby", or "Of Mice and Men")?