Cambridge Greek and Latin Classics. This series provides texts and commentaries on works of Greek and Latin literature aimed primarily at undergraduate and graduate students of either language. With over seventy volumes published to date, it includes both texts traditionally considered canonical and texts which have not enjoyed popularity until recently but are eminently suitable for reading with or by students at those levels. The commentaries discuss texts as works of literature while providing all the guidance with grammatical and syntactical matters needed by today's student.
Collection Budé, or the Collection des Universités de France, is a series of books comprising the Greek and Latin classics up to the middle of the 6th century (before emperor Justinian). It is published by Les Belles Lettres, and is sponsored by the Association Guillaume Budé.
Each title of the series includes an introduction, notes and a critical apparatus, as well as a facing-page French translation. More than 800 volumes of the series have been published, with the Greek authors (approx. 430 vol.) outnumbering the Latin ones (ca. 370 vol.).
The Loeb Classical Library is a series of books, today published by Harvard University Press, which presents important works of ancient Greek and Latin Literature in a way designed to make the text accessible to the broadest possible audience, by presenting the original Greek or Latin text on each left-hand leaf, and a fairly literal translation on the facing page.
The Loebs were not intended for serious research, having only a minimal critical apparatus; nor are they intended for the general reader. According to a member of the Classics department: "More and more are the Loebs becoming a venue for distinguished scholarship, rather than existing simply as cribs for students."
There are some 519 titles currently in print in this sereis, of which 335 are in Greek, and the remainder in Latin.
... and read the essay by Adam Kirsch on the occasion of the series' 100th anniversary.
Oxford Classical Texts (OCTs), or Scriptorum Classicorum Bibliotheca Oxoniensis, is a series of books published by Oxford University Press. It contains texts of ancient Greek and Latin literature, in the original language with a critical apparatus. Since the books are meant primarily for serious students of the classics, the prefaces and notes have traditionally been in Latin.
The Bibliotheca Teubneriana, or Teubner editions of Greek and Latin texts, comprise the most thorough modern collection ever published of ancient (and some medieval) Greco-Roman literature. The series, whose full name is the Bibliotheca Scriptorum Graecorum et Romanorum Teubneriana, consists of critical editions by leading scholars (now always with a full critical apparatus on each page, although during the nineteenth century some editiones minores were published either without critical apparatuses or with abbreviated textual appendices).
Today, the only comparable publishing ventures, producing authoritative scholarly reference editions of numerous ancient authors, are the Oxford Classical Texts and the Collection Budé (whose volumes also include facing-page French translations with notes). (The Loeb Classical Library, with facing-page English translations and notes, aims at a more general audience.)