Plutarch's Lives, Vol. 1 (early second century A.D.) (The Dryden Translation, 1683)

This has to be the very definition of a "classic."  Written in the 100s A.D.; read by everyone claiming to be educated over the centuries (OK, in the west, that is); on every bookshelf where folks could afford to own books; this edition happens to be the Dryden translation (though updated) that introduced Plutarch to English speakers in the late 17th century.  750 pages, so it took awhile to work through at the gym.  Well worth it.

I think it is neat that someone like Montaigne was so fond of the book (in late 16th century).  Not to mention the fictional Cecile in one of my favorite books; her father had Cecile read to him from Plutarch in the evenings (and the Quebec nuns thought this might why be she didn't turn out to be quite as pious as they had hoped) (early 20th century book set in late 17th/early 18th century). Shakespeare used it for "Julius Caesar" and "Antony and Cleopatra".  Etc. - the only source for much information from classical times (if not always consistent and accurate).

Plutarch's three-part method for the "parallel lives" is famous - he selects a leading figure from Greece and provides a short biography, then a biography of a leading figure from Rome, then a brief comparison of the two. (Even if they don't always match up all that closely.)

A few thoughts:

1.  He is interested in the character of the "biographees" - how this helped or hurt them in the long run; hoping this would be didactic for the reader.  Then there is a famous passage in the midst where he allows that the extended consideration of character issues as he writes the biographies is at least as value to him personally as to his intended audience.

2.  The traditional Roman virtues were breaking down, but he does continue to emphasize how successful leaders were circumspect in offering the appropriate sacrifices, obtaining (and following) interpretation of dreams, omens, etc.; augury is presented as incredibly important.

3.  The virtues of thrift; the many leaders that succumbed to avarice; how even virtuous leaders often were brought low, often by schemers back home while the leader was off on some successful military campaign.

4.  Biographies go all the way back to Theseus and Romulus and other figures from legendary times.

5.  I'm always struck by the sophisticated analyses of human nature and political structures in these classical writers - our politicians, not to mention the electorate, could get some useful perspective from reading these things.  In the biography of Lycurgus, for example, a great discussion of monarchy, dangers of popular opinion, strength/weakness of a senate-like body.  As in this book in the context of Athens - much discussion of populism, masses against elites, voting oneselves handouts (with consequences), debt relief (where interest exceeded principal owed).

6.  All the famous characters from antiquity are here, too many to list.  Solon.  Themistocles (ships v. Persia, later banished), Alcibiades, Pericles, Marcus Cato (self-control, austerity).  The story (in the biography of Flaminus) of the shout of joy (by Greeks upon restoration of their city) that caused crows to fall down dead, with Plutarch's speculations on the "why."  Pyrrhus ("one other such [victory] would utterly undo him").  Cimon.  Lucullus fighting all over Asia (and his soldiers tiring as Alexander's had).

Shouldn't be missed.  More readable than expected.  Even the dated translation works well.