One of my all time favorite books, Ender's Game started off a short sci-fi story when Orson Scott Card was but a fledgling writer. Eventually, though, it fleshed out into a series containing, at last count 7 full length novels and many young adult off shoots.
Ender is a young boy, drafted by a military regime, in the hopes that he'll become a brilliant commander. Through his various trials, he is forced to fight against his fellow soldiers - at the age of 6.
Why is this book so amazing? It elegantly captures the human condition. In true OS Card fashion, the characters are so simple and transparent that you ache for them as if you truly know them. As the children experience all their hardships, the reader is caught up in their emotions and pulled deeper into the series. And, despite best intentions of rooting for the kids, by the end of the novel you completely empathize with the adults that made them endure it all.
Not only does it leave you emotionally drained, it also leaves you with several things to consider. Every so often, Card throws in just the right phrase that stands out starkly in your mind. One of my favorites : Human beings are free except when humanity needs them. True to the form of the novel, Card takes on the omnipresent question of choice : when do we stop being free, or, rather, at what point do we stop having a choice?