Der Vorleser by Bernhard Schlink is, in English, The Reader. It was made into a movie a few years ago starring Kate Winslet and Ralph Fiennes. I should emphasize that I am not fluent in German, although I studied it in school, mainly because I have forgotten so much vocabulary. When I read a book in German, I do it slowly and with a dictionary at my elbow. I also do better if I have previously read the book in English.
Der Vorleser isn't the first book I've read in German, but it's been the most challenging so far. I started with Agatha Christies, because I'm so familiar with them that I practically have them memorized. So it's easy to figure out what unknown words mean based on the context. But my goal is to improve my German, reading if not speaking, and I wanted to read original German literature. I started with Die Physiker (The Physicists) by Friedrich Durrenmatt, which is a short play, and not too difficult. (Funny and thought-provoking, too.)
So, having both seen the movie and read the book in English, I decided to try Der Vorleser. Well, thank goodness it has short chapters--I could do a chapter a day, but it took upwards of an hour when I started (considerably less by the time I got to the end). I expected to miss nuances and subtleties, reading without fluency. And I did, some. But surprisingly, I discovered that it's also possible to gain in some ways by reading in a second language, probably because you are forced to pay extremely close attention to every word if you must decipher sentence by sentence.
For example, in the middle section of the book, the narrator describes a troubling numbness he felt toward everything in his life during a certain period of years. The word betauben (to deaden or anesthetize) was used repeatedly in several chapters. For some reason, this word just wasn't sticking in my head, and I found myself looking it up again and again. This section of the book didn't make a particular impression on me when I read it in English, and I passed through it quickly. But while reading in German, repeatedly looking up betauben and reflecting on how it was used, I got a strong sense of the narrator's ennui at this period in his life. And that made the final chapters almost devastating, because those are the chapters in which he feels emotion that actually shakes him, apparently for the first time since his youth.
This type of thing happened more than once, and so I experienced the book more fully in some ways, reading it in its original language. It really makes obvious the drawbacks of reading anything in translation--and the huge benefits of taking a foreign language study all the way to literacy in that language, rather than just to mastery of grammar.