In my opinion this is a classic of the Sci-Fi genre on par with Asimov's 'Foundation' series. I would guarantee that if you were to persue the library of nyone who is a science-fiction afficienado you would find a copy of this book, it's spine bent and cracked and edges of pages discoloured by repeated turnings, sitting on the shelves - and possibly in pride of place.
The story of a child-genius, pushed into military service at the age of 6 to become "humanity's saviour", it follows the life of Andrew 'Ender' Wiggin. Although it is meant to be told from Ender's perspective (and this is really my only criticism of the book), the story comes across more as that seen through the eyes of someone much older than the protagonist is supposed to be. Despite that I found the main character to be emminently likable. The various other major characters were well fleshed out, with their individual virtues and faoibles.
I have no problem rating this book a full '5 stars', and would thoroughly recommend it to anyone seeking an entry-level story into the sci-fi genre.