As an avid advocate of the importance of fiction (I was on the verge of saying "Don't waste the books on science! They can figure that out for themselves... it's written into the universe,"), I freely admit that it's difficult to come up with ten non-fiction books spanning all knowledge.
However...
1. Godel, Escher, Bach (and if I had to pick only one, this would be it)
2. A Brief History of Time
3. On The Origin of Species
4. Relativity Visualized
5. Guns, Germs, and Steel
6. Mader's Biology (yes, the textbook)
7. Longitude (Just to inspire them)
...um...I'll come up with the rest later.