The Lord of the Rings, The entire His Dark Materials series and I, Robot.
They might seem a little sheepish, in that everyone seems to like them, but I think they do with good reason. Truth be told, I already have 3 listed, and, if I had enough space, it would take half an hour to read through my favorites list.
I chose The Lord of the Rings because it really set the bar for me. After I read it, I felt that all the other books I had read were somehow lacking and unimportant.
his Dark materials probably had the biggest effect on my reading. I liked it in the same way that I like LOTR. The epic scale and all that. But what really got me after my third reading of the trilogy (I'm a bit sad, aren't I) was the fact that every time I read it, a different theme seemed to stand out. You could read it as an adventure novel, a love/friendship story or as a sort of religious commentary/criticism. Basically, it made me realize that there was sometimes more to reading that just a story.
I, Robot was actually a surprisingly easy read. It's composed of a series of short stories about the history of robotics after the invention of the "Positronic Brain." What made it stand out for me was the intricacy with which the various plots have been though out, and the way all the stories have such obvious yet unguessable endings. Perhaps the best commentary on human nature that I have read, despite being a book about robots.
I would highly recommend all 3 of these books to anyone who hasn't yet read them.
