Christopher F. Edley, Administrative Law: Rethinking Judicial Control of Bureaucracy (1990) (it provides a good overview and some shrewd insights into ad law; suggested by Dan Markel).
Jerry L. Mashaw & David L. Harfst, The Struggle for Auto Safety (1990) (a book-length case study on why the APA doesn't work, at least unless you take Chevron deference very seriously; suggested by David Zaring).
Foundations of Administrative Law (Peter Schuck, ed., 2012) (very perceptive volume with manageable excerpts from many leading lights in the field, skillfully introduced, connected, and commented on by Schuck; suggested by Frank Pasquale).
Anne-Marie Slaughter, A New World Order (2002) (one of many on global trends; suggested by David Zaring).
The AALS meeting panel on empirical legal studies in adlaw last year a really good intro to the developments in that field (2005) (suggested by David Zaring).
Jody Freeman, Collaborative Governance in the Administrative State, 45 UCLA L. Rev. 1 (1997) (public private trends; suggested by David Zaring).
Donald Hornstein, Complexity Theory, Adaptation, and Administrative Law, 54 Duke L.J. 913 (2005) (excellent article not only for that purpose, but also to get anyone up to speed on some of the more interesting and controversial normative issues in admin law today; suggested by J.B. Ruhl),
Elana Kagan, Presidential Administration, 114 Harv. L. Rev. 2245 (2001) (claiming that the president controls the administrative state, and it's a good thing; suggested by David Zaring).
Ronald M. Levin, Paul R. Verkuil, John F. Duffy & Michael Herz, A Blackletter Statement of Federal Administrative Law, 54 Admin. L. Rev. 1 (2002) (suggested by Frank Pasquale).
Richard B. Stewart, The Reformation of American Administrative Law, 88 Harv. L. Rev. 1669 (1975) (call it the Kuhnian paradigm shift model of administrative law; suggested by David Zaring).
Cass Sunstein, Chevron Step Zero, 92 Va. L. Rev. 187 (2006) (both court-focused and something on the newly complex Chevron; suggested by David Zaring).