Have you ever marveled at the writer's craft? I have, almost every time I read a book. First, you should know that I am an avid reader of fantasy as my favorite genre, though other books are usually interesting if I am asked to read them.
What I find most amazing is how they obviously see the world through a completely different lens than I can see it. How they can describe a scene so you are in it, emotionally, physically, permanently as it sticks in your mind. I marvel mostly about their ability to physically describe their characters. I know that sounds weird, but I have a problem picturing the facial features of a character by their description because I have no idea what an "Aquiline nose" looks like, as opposed to any other. I can pick up on some of the features, like beautiful gray eyes or broad shoulders, but I have trouble taking the written word to a vivid image of a person, and vice versa for that matter. Actually, I am terrified that one day I will witness a crime (traumatic enough) and then not be able to describe the culprit so they can make an accurate enough sketch to catch them. Then again, maybe I am better at it than I think, because I have never really applied myself to describing a person's features. It is still marvelous to me, and I don't know of any way to practice this skill, translating the image of a face or physique into words, so that I can acquire it. It might be worth having though.
Emotional clarity is another hallmark for me of a good writer. I personally struggle with putting my emotions into words and telling a story or scene with emotion in it, so this is a trait that I especially look out for. When authors can tell me the emotion so clearly and move me to giggle with happiness or cry with their characters' pain, they have done their job perfectly. And it usually isn't the bare, bald descriptions, "she was angry" that let's you feel it. It's the showing instead of the telling. Kristin Cashore does it marvelously in Fire, especially one poignant grief scene. Eva Ibbotson is one of the most lyrical authors that I enjoy, with her sweet descriptions of love. There are others, but you don't need a list. :-)
I also love truth. Authors that make you love their characters because they have just as many flaws as me, an because they go through just as many trials. And sometimes their endings are bitter sweet, or just the best they managed to scrape out of the disaster of their lives. A friend told me once that she didn't finish a series, because she could see where it was headed, and she read books for the happy endings. That life was sad and hard enough, that books were supposed to be a happy escape. In a way, I agree, books should be an escape, but it can be just as healing to go through a tragedy with a character as to follow them to their happy ever after. To show the beautiful but heartbreaking part of life ("normalizing" as a counselor would say) to better accept your place in the world. The tragedies that have marred your life and your happiness. This is partly why I love Fire too, because the heroine goes through some terrible tragedies, and the ending is bitter sweet, because you can see how she has been changed by it. Why Zusak's book I Am The Messenger is amazing too. I think denying the real ways things end in life is silly, so great authors tell the truth about life.
Anyway, it said that if you want a happy ending, it depends on where you stop the story.
Writers see the world in a different kind of language. They can take what is in hearts and faces and put it on paper so you understand. They take off the blinders of fairy tales, and tell true stories of life and love and heartache. They speak to a soul with a gift of language that surpasses others, so that you can know as if you have been there. Isn't it marvelous the things they see, and even better, write?