The accelerator's list of milestones is impressive by any standards. The Tevatron announced the discovery of the top quark in 1995, with a measurement of its mass by 2007. The BC meson was detected in 1998, the tau neutrino in 2000, and the Sigmab, Cascade-b, Omegab and Xib baryons detected in 2006, 2007, 2008 and 2011, respectively.
In the Discovery News article reporting the shutdown, Jennifer Ouellette gives an impressive quote from Robert Wilson, the first director of Fermilab. When asked before a congressional committee what the new, proposed Fermilab would be good for, he responded,
It has only to do with the respect with which we regard one another, the dignity of man, our love of culture. It has to do with: Are we good painters, good sculptors, great poets? I mean all the things we really venerate in our country and are patriotic about. It has nothing to do directly with defending our country except to make it worth defending.