As part of my role as a teacher in a sixth-form college for gifted students, I have the option of requesting books be bought for the library. I do also talk about EA with interested students, but am primarily interested here in books that people feel might inspire students who haven't otherwise engaged with effective altruism. As well as obtaining recommended books for my own school's library, I am exploring the possibility of donating highly recommended books to the libraries of other very high performing sixth forms, several of which I already have connections with, and several others I could easily make.
The school already has copies of the 80,000 hours career guide, The Life You Can Save, and Superintelligence, though I am still interested in comments (positive or not) on these. The more details you can add about why you've recommended (or not) a book, the better.
Factfulness by Hans Rosling is currently my go-to recommendation for the most important single book I could hand to a generic person.
Why do I hold it in such high regard? I think that it does a good job of teaching us both about the world and about ourselves at the same time. It helps the reader achieve better knowledge and better ability to think clearly (and come to accurate beliefs about the world). It's also very hopeful despite its tendency to tackle head-on some of the darker aspects of our world.
The other day was my mother's birthday and, not knowing what to buy her, I suddenly remembered this thread and comment, and decided to get her a copy of Rosling's excellent book, which had conveniently just been translated into Spanish.
True, my mother is not a teenager (I'm not that young), but as you point out the book makes a great gift for anyone.