literature

Another friend of mine, located conveniantly in my side bar, (Mimi from bigger than a breadbox) brought up books in her blog earlier this week. (This post is a shameless copy of hers, but I chose a different book altogether to focus my attention on.)
I've always loved to read, I was reading at an early age, before kindergarten, and my parents used to joke that they'd have to win the lottery to keep me in books. I was lucky, they'd frequently get me new things to read. We lived nowhere NEAR a library, so, I got to keep most of the books I read.
I read the "traditional" books people give to children, like Heidi, and Little Women ect, ect.
But I also read everything else. Anything left laying around.
One book, that I got at perhaps, an age too young to understand it, though, was "The Grapes of Wrath", by John Steinbeck. Uncle B got it for me for Christmas one year.
I understood it, though. I was maybe 12 when I read it, but I got it.
To this day, it is one of my favorite books. The imagery that Steinbeck evokes in that book for me. I can imagine the arid dryness of the Oklahoma dust bowl. I can see Tom Joad's prison set of clothing, as he makes his way home to his clan. I can see the old clunker of a car they bought with their last money to get out to the "promised land". I can feel their anxiety, and desperation, and, eventually, defeat and misery as they realize that all that glitters is not gold. The hostility, the pain. That book is truly amazing. I still have the copy Uncle B got me that Christmas. I get it out, and read it again, periodically. I have never seen the movie, and I don't really have a desire to do so. It might ruin my own images.
Surprisingly, though I've liked them, none of the other Steinbeck works have thrilled me like the Grapes of Wrath did.
I've read other great books since that one. But the Grapes of Wrath always stands out in my mind.
So I am going to echo Mimi's question. What book does it for you? Is there one book that should be required reading for everyone? Tell me what it is. Maybe I have not read it, yet.