All of my usual go-to ones have already been said (The Inner Light, Chains of Command, etc.) so I'll add one that I think had not:
Frame of Mind
The ones directed by Jonathan Frakes in general, but that one in particular is just amazing.
Also, I think it's called "Disaster"? The one where Picard is trapped with all the kids and that one girl steps up as "Number One" for the day and then Riker lets her sit in his chair at the end. It's not a perfect episode, but it is just really heartwarming.