5 favorites in every category:

1. Narrative nonfiction:
The Double Helix by James Watson
Endurance by Alfred Lansing
The Right Stuff by Tom Wolfe
Birth of a Theorem by Cedric Villaini
Freedom at Midnight by Collins and Lapierre
2. General/scientific nonfiction
1. 1 2 3... Infinity by George Gamow
2. Code Book by Simon Singh
3. Fermat’s Last Theorem by Simon Singh
4. Emperor of All Maladies by Siddhartha Mukherjee
5. What is Mathematics by Courant and Robbins
3. Biography and Autobiography
1. Einstein by Isaacson
2. Genius (Feynman) by Gleick
3. Lincoln by David Herbert Donald
4. Dirac: The Strangest Man by Graham Farmelo
5. Man Who Knew Infinity by Robert Kanigel
4. Modern Literary Fiction
Lolita by Nabokov
(Yes, next 4 are literary)
Ficciones collection by Borges
Midnight’s Children by Rushdie
Left Hand of Darkness by Le Guin
100 Years of Solitude
5. Science fiction
1. Lord of the Rings
2. Axiomatic collection by Greg Egan
3. Story of Your Life collection by Ted Chiang
4. Dispossessed by Le Guin
5. Forever War by Joe Haldeman