A noncomprehensive and biased list of graphic design books. Some of these books are canon and can be found on myriad lists, others are less referenced. Either way, any would be excellent an addition to your design library.
General
The Elements of Graphic Design by Alex W. White
Design Elements by Timothy Samara
Basic Visual Concepts And Principles For Artists, Architects And Designers by Wallschlaeger and Busic-Snyder
Typography: Macro and Microaethetics by Willi Kunz
Graphic Design, Referenced by Bryony Gomez-Palaci and Armin Vit
Typography
Thinking with Type by Ellen Lupton
The Elements Of Typographic Style by Robert Binghurst
Typographie: A Manual of Design by Emil Rider
Stop Stealing Sheep and Find Out How Type Works by Erik Spiekermann
Typographic Systems of Design by Kimberly Elam
Typography by Denise Gonzales Crisp
Typography: My Way to Typography by Wolfgang Wiengart
Typographic Design: Form and Communication by Carter, Meggs, Day, Maxa
Layout/Grid
Making and Breaking the Grid by Timothy Samara
Grid Systems in Graphic Design, Joseph Muller-Brockman
Theory
Design Studies: Theory and Research in Graphic Design by Audrey Bennett
Graphic Design Theory by Meredith Davis
Understanding Comics: The Invisible Art by Scott McCloud
Branding
Brand Thinking and Other Noble Pursuits by Debbie Millman
Designing Brand Identity by Alina Wheeler
Game Design
Rules of Play: Game Design Fundamentals by Katie Salen Tekinbas
Web Design
Don’t Make Me Think by Steve Krug
History
Meggs’ History of Graphic Design by Philip B. Meggs
Graphic Design History, A Critical Guide by Johannna Drucker and Emily McVarish
Graphic Design: A Concise History by Richard Hollis
100 Ideas that Changed Graphic Design by Heller and Vienne
Other
How to be a Graphic Designer without Losing Your Soul by Adrian Shaughnessy
On Photography by Susan Sontag
Image/Music/Text by Roland Barthes
A Smile in the Mind by Beryl McAlhone
A Designer’s Research Manual by O’Grady
Visual Research: An Introduction to Research Methodologies in Graphic Design by Ian Noble and Russel Bestley
The Visual Display of Quantitative Information by Edward Tufte