We absolutely loved the Invention.... book at our house. I bought it in Canada last spring and has been recommending it to people ever since. Even Scholastic Book Fairs carry it now:-)
As for George's ....., I think this book is great. The first few chapters are kind of different than the rest of the book, so don't get discouraged and read on! Available also through Scholastic, but if you are a savy shopper, Amazon has a great price (like $12 versus original $17).
I should also mention The Periodic Table - Elements With Style by Adrian Dingle and Beowulf in a graphic novel edition by Gareth Hinds.
Happy reading:-)