Shopping Help?

Hey, fellow readers. I hereby ask for help. I have two nephews, ages 8 and 6, and I’ve got no idea what titles to get them for Christmas this year. I am the Book Aunt, so I have to get something cool and interesting, and readable, but while there are often age recommendations on the fly-leaves of books, there’s no such thing as children insurance that guarantees the child in question will like what you send.

So, suggestions please: What’s are good titles for bright, kinda geeky but leaning more toward engineering geekery than computer geekery, boys?

(Girl books? No problem).

If it helps, in previous years they’ve received Where the Wild Things Are and In the Night Kitchen, and stuff like that.

I’m more about classic titles that hold up than trendy stuff.

And I prefer to buy hardcovers.