I thought I'd make a plug for the Letters of Saint Basil, as they'll be closing this Friday.
From The Greek Fathers:
No one really knows St Basil who has not read his letters. There are 365 altogether (XXXII 219–1110), in which he writes of every kind of subject, details of his own life and events in the history of his time, dogma, polemic, practical advice and controversy. Sometimes he consoles some one for a loss, sometimes he asks a favour or thanks his correspondent for a favour already received. We find in them politics, discussions of points of scholarship, anecdotes of every kind. He corresponded with all sorts of persons from the Pope to heretics; he writes to governors, officers, monks, nuns, bishops, to the great Athanasius, his own relations, his clergy; most of all to Gregory of Nazianzos; even to Apollinaris of Laodicea, of unhappy memory. Sometimes he is angry and complains, sometimes he describes the country where he is; he constantly makes quiet fun. In his own time these letters were famous; Gregory of Nazianzos began collecting them at once after his death. There is certainly no collection of Greek letters so entertaining as these.2
(2) They make a perfect parallel to the Latin letters of St Jerome († 420) both in their interest, humour and pleasantness, and in their beautiful style. For St Jerome, in spite of the shocks he sometimes gives us in the Vulgate, could write most beautiful Latin when he chose.
And, from Cardinal Newman, on the reading of the letters of saints (and of St. Basil in particular) :
A Saint’s writings are to me his real ‘Life’; and what is called his ‘Life’ is not the outline of an individual, but either of the auto-saint or of a myth. Perhaps I shall be asked what I mean by a ‘Life’. I mean a narrative which impresses the reader with the idea of moral unity, identity, growth, continuity, personality. When a Saint converses with me, I am conscious of the presence of one active principle of thought, one individual character, flowing on and into the various matters which he discusses, and the different transactions in which he mixes. It is what no memorials can reach, however skilfully elaborated, however free from effort or study, however conscientiously faithful, however guaranteed by the veracity of the writers.…
When I read St. Augustine or St. Basil, I hold converse with a beautiful grace-illumined soul, looking out into this world of sense, and leavening it with itself; when I read a professed life of him, I am wandering in a labyrinth of which I cannot find the centre and heart, and am but conducted out of doors again when I do my best to penetrate within.…
Now, in the ancient writings I have spoken of, certain transactions are thoroughly worked out. We know all that happened to a Saint on such or such an occasion, all that was done by him. We have a view of his character, his tastes, his natural infirmities, his struggles and victories over them, which in no other way can be attained.’
Finally, from The Post-Nicene Greek Fathers:
To trace Basil’s correspondence fully would be to write the history of the Church in his day, to fathom its controversies, to point out its secret and open enemies, and to detail the unhappy relations of the East and the West.
This looks like an excellent resource for Orthodox Christianity, Church History, and even simply devotional reading. And, as a added benefit, you get the Greek. 
