I'll start - S02E09 Measure of a Man
This is my favorite TNG episode for a couple of reasons. First, it shows that they didn't need amazing effects and set pieces to drive the story - most of this ep consists of the actors sitting in a single set and talking, yet the story is still fantastic and the episode is riveting.
Next, this is my favorite because Data is my favorite Star Trek character overall, and I feel this episode is a key piece of his character's development.
I really liked I, borg. by contrast I didn't think much of "the inner light" which I believe was the top rated episode.
but I definitely did enjoy measure of a man. a lot of the star trek court episodes are excellent, I think, across all the series of that time period. (the tng opener being a notable exception 🤣)
I, Borg is also great and for many of the same (or similar) reasons as Measure of a Man. Star Trek seems to be at its best when it's using high-concept sci-fi to explain very basic things about our interactions with other people.