These three comprise one story in the end, but I will include it anyways: The Lord of the Rings trilogy.
To this day I am hard pressed to think of another set of books that have had such a profound impact on the world, both literary and otherwise.
The authors that still credit these works, or pay homage to the ideas and concepts within, are without end.
More than that, the story itself takes place in such a rich and detailed world. It tells a tale that is in many ways the exact opposite of what one would expect. Yes, there is the bad side, and the good side. Yes, there are adventures, fighting, intrigue and politics. But where it differs is that at the heart of it, good wins, but not from physical might, or being smarter, better equipped, or the incompetence of the “bad guys”. Good wins because the hero is a kind, simple creature that does not desire power. He shows mercy where others, and perhaps justifiably, would not have.
This kind of different and difficult perespective is an accomplishment in and of itself. Taking place in such a timeless and epic tale is something everyone should experience.