Updated with more detail: Question copied from Eric Jorgenson, who posted the same question on twitter: https://twitter.com/EricJorgenson/status/1016003656787857409

(have an upvote)

IF I were that interested in a book,(THEN) I'd just learn the language of the original (Sanskrit for the BG) and read the original. Most translations miss many nuances.

Hey, that's a great idea! I think I'll take that on. Learning Sanskrit would be great, and reading the original BG would be so much better, you're right.

Just a heads up. Unless you have a flair for languages, you are in for a lot of pain. It will be exacerbated if you are a native English speaker with no knowledge of other Indo European languages like French or German because Sanskrit has ridiculous amounts declensions. (English, thankfully, lost those; it would have been much worse had they survived.) To add to this, the script is quite complex, more complex than Arabic but far less than Japanese (not sure how people manage to use such a complex system), but this can be somewhat ameliorated by using a transliterated text, like the ones Indologists use.

Thanks for the warning! Luckily I've already studied languages with (some) declensions like Old English, Old Norse and Icelandic, and to a lesser extent Russian and Bosnian. I used to be ravenous to learn new languages but after college and children my attention/interest/time shifted, but I think I can make time for some Sanskrit :)

Well, in that case, the road won't be as bumpy. You might actually survive and reach the other end. :)

Which ones have you read? I liked Eknath Easwaran's translation.

I've read the translation by Purohit and by Prabhavananda, and moving on to Easwaran's next.