Hare Krishna,

i am opening this thread to share opinions about commentaries to the Gita other than the prominent one written by Bhaktivedanta Swami Prabhupada.

Keep in mind that all these "supplemental" commentaries are in some way or another authorized; in fact, some were written by Godbrothers of Prabhupada, others by his direct disciples, and so forth.
They are, from left to right (see the image attached to this message):
-Bhagavad Gita as it is by Bhaktivedanta Swami Prabhupada
-Srimad Bhagavad Gita- The Hidden treasure of the sweet Absolute by Srila Bhakti Raksaka Sridhara Maharaja
-Bhagavad gita- The Song of God by Swami Mukundananda (disciple of Jagadguru Shree Kripaluji Maharaj)
-A Comprehensive guide to Bhagavad Gita by H.D. Goswami
-Bhagavad Gita by Swami Narasingha
-Gita Darsan as Bhakti yoga by Bhakti Hridaya Bon

Besides these commentaries, you will find an image of "Prema Rasa Siddhanta", which despite not being a Gita commentary is a worthy book that i can only compare to "The Nectar of devotion", and that i would recommend anyone to read.