Best are the "Practicing to take the"......(Economics/Physics etc.)
book
series from ETS, who produce the actual GRE
advanced subject exams. These
are not study guides but past examination papers. They are THE best
indicator
of what you know, what you don't know, and where you should concentrate
your efforts within the relevant discipline.
Most of the study guides from other publishers are of limited value.
One
notable exception is the series from THE PRINCETON REVIEW called
"Cracking the GRE"... (Biology, Literature, Psychology). I've used
the
psychology offering and found it useful. The study notes are directly
applicable
to the GRE subject exam. The test questions are very close in level
of difficulty
and in scope to that of the actual exam. There are full answers to
the questions
in a subsequent section. Unfortunately, only 35 questions are included.
So far
as I know the series only covers the three exams listed above; pity.
The Research & Education Association (REA) publishes a series of
preparation
guides for all the subject exams. These usually contain more than one
full mock
exam with answers (e.g. the mathematics book contains six full exams)
and
many of the books provide study notes. I found the study notes in the
political
science guide quite useful. However, the level of difficulty and focus
of the
questions did not reflect that of the actual GRE subject exam. This
seems to be
a common trait in the REA series.
Other study guides from Arco and Barron's I found more a hindrance than
a
help.
In summary,
ETS "practicing to take" series: MUST BUY
Princeton Review "Cracking the GRE" series: BUY (if subject applicable)
REA "preparation for the GRE" series: BUY (with reservations)
Arco/Barron's: keep your cash, buy a pizza
The books can be found at Barnes & Noble, Borders and other retail
outlets or
from Amazon.com
on the Web.
Finally, Regents College
produce reading lists for many of the GRE subject
exams. Unsure if these will be readily available to you though. Try
nosing
around the website and maybe you'll get lucky.