Sybil (fiction based on a true story about a dissociative personality)
The Many Faces of Eve (by Freud I think)
No One Promised You a Rose Garden (technically fiction)

I think the Man Who Mistook His Wife for A Hat by Oliver Sacks would also be great high school reading and is short vignette-based non-fiction. Musicophilia is also good, just longer and more specific.

Proust and the Squid about the brain’s development of reading may be good for advanced readers who don’t mind wading through some technical terms for parts of the brain.

I read Why Zebras Don’t Get Ulcers in college and I don’t think it’s appropriate for high schoolers. Even in college I felt it was too long and a bit difficult to wade through. The concept behind it is great and fascinating, but a bit wordy.

“Stardust” – John Gribbin really struck a chord with me when I read it. That we are literally made of the remnants of stars is a real awe-inspriring concept.

“Eating The Sun” – Oliver Morton, about the wonders of chlorophyll/photosynthesis is another good one.

(I can see my credit card is going to get a workout with all these recommendations I’ve yet to read!!)

I wouldn’t assign Gödel, Escher, Bach to highschoolers, as one commenter suggested, but I think I Am a Strange Loop, also by Douglas Hofstadter, would be great.

Stiff by Mary Roach would also be both enlightening and entertaining. Actually, pretty much anything by Mary Roach would hold highschoolers’ interest, although depending on the maturity of your students you might want to skip Bonk. She’s also got a new book coming out this fall called Packing for Mars: The Curious Science of Life in the Void, which looks like it should be pretty interesting.

Not a single recommendation for the three things that everybody, not only HS kids, needs to know, and which are the least taught (if taught at all):

1. How to think – not just how to critique an argument, but how to construct and communicate valid (verbal) arguments;

2. How to solve problems – eg try G. Polya’s ‘How to Solve It’ if you have trouble with mathematical (and other) problems;

3. How to learn. Effective learning isn’t just naturally inbuilt, you know. Like all human skills it’s learned and polished over years.

But if you insist on mere “stuff”, how about: ‘Against the Gods: The Remarkable Story of Risk’ by Peter L Bernstein.

Big Bang by Simon Singh
The Canon: The Beautiful Basics of Science – Natalie Angier

General Science:
Bryson’s A Short History has been mentioned before, I concur
Natalie Angier’s The Canon
What about having them pick pieces from recent collections of The Best Science and Nature Writing?

Evolutionary Biology
Sean Carrol’s Endless Forms Most Beautiful
David Quammen’s The Song of the Dodo
Neil Shubin’s Your Inner Fish

Biography
Barbara Goldsmith’s Tortured Genius (Marie Curie)
David Bodanis’s Passionate Minds (Emilie du Châtelet and Voltaire)
David Quammen’s The Reluctant Mr. Darwin

Anthropology
Anne Gibbon’s The First Human
Richard Wrangham’s Catching Fire
Pat Shipman and Alan Walker’s Wisdom of the Bones
Robert Sapolsky’s A Primate’s Memoir or Monkeyluv

Physiology/Anatomy
Robert Sapolsky’s Why Zebras Don’t Get Ulcers
Natalie Angier’s Woman: An Intimate Geography (for people of all sex/genders)
Jill Bolte Taylor’s My Stroke of Insight
Susan Barry’s Fixing My Gaze
Sheril Kirschenbaum’s The Science of Kissing (it’s not too racy, and I think high schoolers would be really interested, plus it has good advice about how powerful hormones are!)

Health/Medicine
Molly Caldwell’s Asleep and also her The American Plague
Sanjay Gupta’s Cheating Death
Philip Yam’s The Pathological Protein
Sonia Shah’s The Fever

Physics/History
Joshua and Anne-Lee Gilder’s Heavenly Intrigue

Chemistry
Sam Kean’s The Disappearing Spoon

Math
Charles Seife’s Proofiness
Jennifer Ouellette’s The Calculus Diaries

Ecology/Climate change
Rachel Carson’s Silent Spring
Wally Broecker’s Fixing Climate

I should stop. Never have I wanted so much to take a month off and re-read all of these and everything mentioned by others before me!

A Feeling for the Organism — Life and Work of Barbara McClintock by Evelyn Fox Keller

The Statue Within — Francois Jacob’s autobiography. Discussing the book with a French colleague, he asked about the English translation. I called his writing poetic, and he replied that it must have been a good translation. Only about a 1/3 of the book is directly about biology, but the mind of a scientist shines throughout.

The Red Queen and Crick’s biography by Matt Ridley.

Einstein — His Life and Universe by Walter Isaacson

Microcosm by you know who.

The Elegant Universe
and
The Fabric of the Cosmos
by Brian Greene

and Simon Singh’s absolutely excellent “trilogy”:
Fermat

Perhaps more mind bending are books from Douglas R. Hofstadter, like Gödel, Escher, Bach: An Eternal Golden Braid and The Mind’s I. Gödel, Escher, Bach touches on what it means to be conscious and how that might apply to artificial intelligence In addition, Hofstadter introduces concepts like computability, recursion, and number theory. The Mind’ I is a collection of essays that delves even more deeply into the mind and self.

Mind Hacks: Tips & Tools for Using Your Brain by Matt Webb is a fun and practical collection of “tips” that are probably better described as tricks relating to the mind. Each tip is short and many have practical activities and experiments the reader can do to investigate further.