Edward Tufte's books are nice and dry, although his field is data visualization rather than pure layout and typography. Bruce Mau's "Lifestyle" also comes to mind.

uncanny: the art and design of shawn wolfe
buro destruct
john maeda: design by numbers
if/then play: design implications of new media
tolleson design
paul rand by steven heller
process; a tomato project
piet zwart: the typographical work 1923-1933

yes tolleson's 'soak wash rinse spin' is good

thx for the title oregon, couldn't quite remember it.

John Maeda's 'Maeda@Media' is quite good too.

try 'typographie' by otl aicher
(German Classic)
seems like itout of print
but maybe you can still find it

on the aicher tip, 'the world as design' is a good one. many essays on design >> graphics, architecture, and industrial design.

Willi Kunz : Typography-Macro and Microaesthetics

Any text books written or co edited by Steven Heller are good theory books. Check them out at http://www.allworth.com

The Looking Closer Series- 1,2,3 and 4 should be in any graphic designer's library.

Quentin Newark : What is Graphic Design? Published by Rotovision is a great start is finding out the real meaning and reason behind graphic design. Highly recommended.