There are many translations, of course, and I certainly have not read them all in order to make a choice as to which is the best. The version I own is a translation by W. J. Johnson published by the Oxford University Press.
The chapter 58 of Sons of Gods is a much condensed version of the Gita, and not a translation of a selection of verses: it's what I believe to be the essence of Krishna's message to Arjuna on the battlefield of Kurukshetra. Much as I would have loved to include the entire Gita, doing so would have broken the word limit I had set for myself and held back the story. I do encourage everyone to get their own copy of the entire Gita and read it whenever they can; of course, online versions are available for free, but there's nothing like holding this book in your hands, packing it into hour luggage when you go on a trip, slipping it under your pillow when you go to sleep. It just doesn't do to have it on your Kindle along with a thousand other books.
For those who have not yet read Sons of Gods, or any Mahabharata at all, here's the context of the Gita:
Krishna, who is the incarnation of Lord Vishnu, gave his friend Arjuna the choice when it became clear that the Pandavas--Arjuna and his five brothers, who live in Righteousness--must go to war with their cousins, Kauravas--Duryodhana and his 99 brothers, who have taken the kingdom from them by unrighteous means.
Krishna is also a cousin of the Pandavas, and he commands an army that is known to be invincible: the Vrishnis. According to the rules, Arjuna and Duryodhana both approach Krishna to ask him to be their ally in the great battle, and according to the rules, Krishna is duty bound to ally himself to whomever asks first.
Duryodhana enters his chamber first, finds Krishna asleep, and so sits beside his head to wait till he awakes.
Arjuna enters after Duryodhana, and sits at Krishna's feet, where he sinks into meditation. Krishna wakes up, opens his eyes, and sees Arjuna first.
Duryodhana, however, insists that chivalry demands that Krishna side with him, as he was there first. Krishna only smiles, and says, "but I saw Arjuna first." What a conundrum! To solve the problem, Krishna gives the cousins a choice: on the one side his mighty army, the Vrishnus, who cannot be defeated. On the other side he alone, as a charioteer. He will not fight: he will only drive the chariot.
To Duryodhana's fury, Krishna gives Arjuna the first choice: what will he have, the entire army, or he himself, weaponless, as a charioteer?
Arjuna does not think twice. He folds his hands in prayer, sinks to his knees, and says: "I want You my Lord; I only want You."
For me, that is one of the most poignant, the most moving, the most important scenes in the entire Mahabharta. To me, Arjuna's answer contains the whole Gita in itself.
In the coming days I'll be going through the Gita -- the condensed version as posted on this page -- but I'll start with that sentence: I want You, my Lord. I only want You.