After a lot of thought, I have decided on Speaker For the Dead by Orson Scott Card. Truly, it's an intelligent, thought-provoking, and emotionally engaging novel that I absolutely could not put down (any of the times I've read it).
This book is the one that Card set out to write that ended in the publication of Ender's Game. He felt Andrew Wiggin's past could not be squashed into a chapter or four at the end of the book without sacrificing the character's humanity and betraying his vision for the novel. Though much more widely known and read, Ender's Game is, really, a prequel. More "entertaining", surely, and a very worthwhile read, but lacking the earth-shaking effect of Speaker For the Dead, it's raison d'etre. It is quite literally a read that can change your life, if you simply allow it to do so.
Allama, another perfect decision. Well done!
Well, I stand corrected. I had somehow forgotten about the Ender Quartet; Children of the Mind is therefore tied with Watchmen on my list. Ender's Game was spectacular, as was Speaker For the Dead. Xenocide was a good book, but did not leave the mark on me that its two predecessors left. However, I would have to say that the conclusion to the quartet, Children of the Mind, is the best in the series. Its writing is exquisite and beautiful, and the resolution is wrapped up quite well. I think I'll go and re-read them all now! :)
The final words of the series should be held in the highest esteem: **Allama, if you haven't read this yet, shield thine eyes!*
Jane closed her eyes, smiled, and then all four of them were gone. Only the mothertree remained in the middle of the clearing, bathed in light, heavy with fruit, festooned with blossoms, a perpetual celebration of the ancient mystery of life.