Response to Tufte font
The serif font is Monotype Bembo (in lead!), found on the jacket of The Visual Display of Quantitative Information (1983, 2001) and on Envisioning Information (1990).
The sans-serif font on the jacket of Visual Explanations (1997) and on the cloth spine of Envisioning Information is Gill Sans, optically letter-spaced.
The fonts on the cover of the essay "The Cognitive Style of PowerPoint" (2003) are "ETBembo," a computer version of Bembo that Dmitry Krasny and I constructed just for use in my new work (now that the type is set in Quark, not lead) and the cartoon font is "Wild and Crazy" which I found for $29 on the internet. "Wild and Crazy" also comes with a nice set of thought balloons.
Mattew Carter's Bell Centennial and Gill Sans are used for some tables; see, for example, Envisioning Information, page 105, for redesigned timetables.
-- Edward Tufte