It’s something of a stretch, but one might consider all seven Harry Potters a single work. Obviously Lord of the Rings is, and that’s not a stretch at all. The Narnia books aren’t, though.
My son read The Little Prince in 7th grade I think. “Mom, that was the most BORING thing I ever read.” 
I keep telling him to read Waiting for the Galatic Bus by Parke Godwin. Now if X-box put out a version of it we’d be in 
Simon Singh’s Big Bang
Either Mere Christianity or The Screwtape Letters by CS Lewis.
My Side of the Mountain
When I was a kid, I was totally convinced this was non-fiction. I mean, he gave you all the blueprints and instructions right there! I thought it was a great idea to take off and live alone in the woods, and at the same time, thought his parents should be arrested. 
I think we should allow potential or even imaginary children into this thread. But only the ones that like to read.
And just a quick warning: DON’T EXPECT YOUR KIDS TO LOVE THE BOOKS YOU DID.
Most of the books I just lovvved as a kid leave my kids cold. And it’s heaet-breaking.
I contend that Milne and Thurber and Doyle and Poe DO indeed hold up well, it’s just an irrational case of “What Clicks With Your Kid”. One of my kids gave up on a book of Bradbury I got him and devoured “Helter Skelter” instead!
The only thing we’ve all agreed on is Twain and Rowling.
If I had to pick one, probably Pippi Longstocking. I know, I know, it’s hardly great literature, and encourages all sorts of horrendous behavior. But the girl, you see, is the strongest and best at just about everything. She is completely independent, and accepting of alternate ways and thoughts. She even excels specifically because she thinks differently.
Without Pippi I might well have spent my entire life trying to fit into the Stepford Wife mold my parents tried to force me into. :: shudder ::
I’m going to need you to take that back.
Um…what’s your point?
Pippi is a wonderful, wonderful character, I agree. Anyone who says differently is selling something.
I don’t even like dogs but I think **Where the Red Fern Grows **is a tremendous book. One of my favs as a kid.
For little girls:
The Country Bunny and The Little Gold Shoes by Du Bose Heyward. I didn’t know it at the time, but it was my first exposure to feminism. The Easter Bunny is a female with about a dozen baby bunnies to take care of, too.
For adolescent girls & further liberation:
Pippi Longstocking. Any little girl who can carry a monkey on one shoulder & a big white horse on the other & stop as she’s walking down the road to wiggle her butt, just because it feels good, is okay with me.
Orson Scott Card! I haven’t thought of him in years. Incredible writer.
And along that vein, a woman who had just turned 100 was asked what she thought the best invention was. She said, “Electricity.”
I should have added…pubescent girls:
Little Women. “Safe” love, laughter & lessons.
Lord of the Rings.
I chose this because of the way the question was worded. I would want my children to know the book above all others, and to me that means it would represent what I wanted them to know about life. It would represent who I am, and how I want them to live, and what I thought was important in life.
Recognizing, of course, that they might totally disagree with me. That’s the chance one takes.
Lord of the Rings includes adventure, heroism, courage, dedication, faith, loss, and change. It’s spiritual and fantastic, but also pragmatic and down to earth. Best of all, it’s well-written, and as a writer that’s tremendously important to me.
Now that I think of it, I first tried to read Fellowship of the Ring when I was ten. Too early. I found it boring. What’s important is that I tried to read it because it was in my father’s library. Until this very moment, I never saw how significant that was. I could not see then how much it says about him that he had this book in his library in 1963. It’s also significant that he had a library to begin with, and that he let me have free run of it.
This question, though, is rather like the story of the man who asked Hillel to explain all of Tanach standing on one foot. One book is a start. Choose the good ones early on, and you’ll give something rare and wonderful to your children.
Agreeing with others, To Kill a Mockingbird.
I don’t think there’s a better statement I’ve ever seen of what it means to be Good.
They’re going to read The Phantom Tollbooth. And then they’re going to read it again and again until they like it! (“Screw the vegetables! You’re not leaving this table until you finish reading about Officer Shrift young lady!”)
This is my answer, too. I still read this book all the time. It’s on my Kindle!
I can’t believe how many people my age (32) I’ve met who’ve never heard of this book!!! It’s one of my all time favorites!
I know you’re not asking for the first book, but one I found my kids liked as toddlers (as well as me) is a very, very basic one that’s kind of a tone-setter, The Carrot Seed. Of course, it can be a little off-putting these days to hear all those adults telling a little kid he’s going to fail, but whatever.
all different at different ages isn’t it, but at very young:
winnie the pooh (not the horrendous disney books that i’ve seen though, that rewrite the stories without an ounce of wit or charm! :mad: