Ring-like deposit formed from a drying drop with suspended microspheres.

 

While they are only up to 2003, two Complex Systems professors have the 'Milestone article' in three of the publication years.  The Milestone Article list to date can be found HERE.

First up, in 2000 is an article by Robert Deegan et al:

Contact line deposits in an evaporating drop
Robert D. Deegan, Olgica Bakajin, Todd F. Dupont, Greg Huber, Sidney R. Nagel, and
Thomas A. Witten  Phys. Rev. E 62, 756 – Published 1 July 2000