Agreed with others about Measure of a Man. It's good, but the big problem I have with it is that Riker's defence completely sucks. The writers want Picard to win, and so Riker never makes a single good counterpoint. Seriously, switching Data off is one of the big centrepieces of his case, which isn't even vaguely relevant to the question of whether or not he's sentient.
I love Time Squared, it's one of my favourite episodes not just of Season 2 but of TNG as a whole, although the points about it being annoyingly ambiguous are all fair. Future-Picard has a great line where he cryptically suggests that the vortex is actually alive and sentient, and targeting him on purpose for some unknown reason, and that always stuck with me. I wonder if it was actually benevolent, and trying to force Picard into the shuttle each time so that he'd escape the explosion and could be sent back to give the crew another chance to escape.