It was the closest to Big Concept Sci Fi, as opposed to space opera, in the ST ouvre, so it remains my favorite. Also the best music of the franchise. "Ilia's Theme" is gorgeous. Speaking of gorgeous, the Enterprise refit was the most beautiful iteration of the Connie class.
https://www.youtube.com/watch?v=QJZ_agVJqu8"
I am not a nerd.