I have read Lord Krishna’s Bhagavad Geeta many times in Sanskrit, Hindi and English.
My understanding is that originally Bhagavad Geeta was written in Sanskrit. Therefore my recommendation would be to read it in Sanskrit. The next nearest to Sanskrit is Hindi version (photo attached).
English translation is good to an extent say for very basic understanding however, for advanced understanding I would say it should be in Sanskrit.
It’s like watching ‘Fools and Horses’ looks damn good when Del Boy and others are performing, that version is authentic or ‘Friends’ which is fantastic to see Joe or Phoebe version. If one tries to copy you don’t get the same feeling. Similarly, spiritual texts written in spiritual language which is Sanskrit, all texts should be read in that language. This is my opinion.