I'd throw in The Great Brain[1] books, any of the Tom Swift Jr.[2] books, the The Three Investigators[3] books, and the Encyclopedia Brown[4] series.
Edit:
Remembered a few other suggestions... Pretty much anything by Jules Verne, especially The Mysterious Island. Definitely some HG Wells, and definitely some Choose Your Own Adventure books (anybody remember The Cave of Time?)
Glad to see A Wrinkle in Time and The Mad Scientists Club on the list. Those were awesome reads as a kid.
I guess he's not very popular in the states, and thus my Soviet upbringing is showing, but I can't imagine growing up without him. I learned pretty much all of the geography that I know from him.
Verne suffers from a lack of good translations in English. Most of them are abridgments of public domain Victorian translations. They get the science wrong, they introduce British 19th-century racism, they rename characters for no reason (Axel -> Harry, Lidenbock -> Hardwigg), and they eliminate Captain Nemo's anti-British rant because after all, he's a wog.
That being said, no child's education is complete without "Around the World in 80 Days" and "Journey to the Interior of the Earth."
There's a F.P. Walter translation of "20,000 Leagues Under the Sea" which is both modern and donated to Project Gutenberg.
The North American Jules Verne Society has a list of works, a determination of which are the best translations, and links to Amazon here: http://www.najvs.org/works/index.shtml
Yeah, Jules Verne was awesome. His stuff is fairly popular here in the US as well, although I can't compare to how popular he was elsewhere. I read several of his books when I was younger. The Mysterious Island was always my favorite.
I can speak for how popular he was during the Soviet Union. As a pre-teen male, you were less than human unless you've read the Nemo/Grant/Island trilogy.
Don Quixote needs to be on this list. I started it a few years ago and every time I pick it up I feel like a kid inside. If my parents had read that to me chapter by chapter, from age four on I think I would've been in bedtime heaven.
A bit more obscure, but tremendously fun (and very geeky), are George Gamow's Mr. Tompkins books (http://en.wikipedia.org/wiki/Mr_Tompkins) - I discovered the first two in my high school library, but they would be very accessible to any elementary school child.
I witnessed university faculty squabbling, debating, supporting arguments, and a lot of years of experience and input go into the reading list for students, and this was an Ivy League school. Although this was obviously a different level, I would suppose considering the absorption rate of children that a reading list should be taken very seriously and I would make sure those who put it together were qualified to do so.
I'm very surprised (and pleased!) to see my favorite YA author, John Bellairs, show up on here, although I am a little questioning of The Lord of the Rings for kids under 10 - it's been a long, long time since I read them, but I wonder if someone that young would be able to keep track of the different characters' journeys.
It's worth it. A great aunt bought me the Hobbit when I was around five, and I immediately took to the whole Lord of the Rings series, Silmarillion, etc. By 10 I'd read every Tolkien book I had ever heard of, including ones by his son that I didn't even realize. My best friend to this day was just as freakish, and it turns out not only was it pretty much what taught us how to read, but we kept track of many of the characters and stories the same way– by drawing all of it. Personally, without them I don't know if I would have appreciated books, period. Some kids will go to great lengths to match with the things they're given, so there's certainly no harm in gifting a copy of at least the Hobbit and testing whether or not they'll really enjoy it.
Yeah, I got some heat from other GeekDads when I put that on the original GeekDad list. But truth be told we have now read LOtR to two 8 year olds. The hard part is to get them to Rivendell. Once there the story takes over and it works. I included it because it is what _I have_ read aloud to two of my kids. Erik Wecks (GeekDad)
Kids are often smarter than you give them credit for, especially if they are engaged in the subject matter. Kids which are obsessing over something have remarkable retentive abilities.
My 3rd grade teacher read this to my class, and I, to this day, think of the phrases "a basement" and "in grey she ate" when I hear those words thanks to this book.
One,Two, Three, Infinity is probably the best possible introduction to math for kids.
The big challenge is skipping ahead to the "cool stuff" for kids who are still young enough to lack facility with algebra. Most attempts to do this are either hand-waving or unfairly advanced. But the real solution is to show them genuine math that doesn't require any solving for x, like Cantor's diagonalization lemma.
