Classical mechanics will take up a large portion of the test and for me those were the problems that I would tend to get stuck on (particularly collision problems). A few days before the test I went through Young & Freedman and solved a bunch of the momentum, torque, and energy problems. Something that I also had to review a little because it would throw me off a lot was sign conventions in optics for radii, s, s', foci. Relativity, also, should definitely be practiced.
If you don't know anything about particle physics, a quick overview shouldn't take long and should get you one or two added points. Electrons, muons, and taus are leptons, baryons have three quarks (protons, neutrons), mesons have two quarks, weak interaction doesn't obey lepton number conservation, neutrinos usually come up in particle equations to conserve lepton number, processes are usually mediated by the weak interaction in decays.
Positronium has half of the zero point energy of hydrogen because its reduced mass is lower by a factor of 2.
Everything that will be on the test is listed on the ETS site and the practice tests give a good representation of the topics.