There was an article a couple of years ago that did a top x TNG episodes, that I can't find now (argh!). Anyway, part of the way through, when it was obvious that the top two were going to be "Darmok and Jalad at Tanagra" and "Inner Light", one of the compilers complained that they weren't "Star Trek" episodes. Which was obvious nonsense, because "to explore strange new worlds; to seek out new life and new civilizations" is right there in the intro.
And TNG does that, probably better than the others, it actually thinks of ways other civilisations might be different, as in Darmok, when they communicate in a different way.
Those are my favourite episodes, where the crew have to handle the different, and the way they sometimes don't, or it takes them a long time to do it.
Several of my favourites are the ones everyone else hates or doesn't rate, where there's a odd alien culture and weirdness happens, like 'Masks' or the one where the Enterprise's computer produces an offspring.
But yes, my favourite is "Inner Light". There's this civilisation and they know they're going to be wiped out, and there's no way of getting out so they send their culture instead, because that they can save.
Day 1 -
Favorite TOS EpisodeDay 2 -
Favorite Federation RaceDay 3 -
Favorite StarshipDay 4 -
Favorite CaptainDay 5 -
Saddest eventDay 6 -
Happiest event Day 8 - Favorite Federation Enemy
Day 9 - Favorite Character
Day 10 - Most Shocking Moment
Day 11 - Crew Position You Would Want
Day 12 - Crew Position You Wouldn't Want
Day 13 - Favorite DS9 Episode
Day 14 - Favorite Time Travel Episode
Day 15 - Favorite First Officer
Day 16 - Favorite Voyager Episode
Day 17 - Favorite Trek Novel
Day 18 - Favorite Non-Aligned Race
Day 19 - Favorite Enterprise Episode
Day 20 - Character You're Most Like
Day 21 - Least Favorite Character
Day 22 - Favorite Trek Film
Day 23 - Best Trek Tech
Day 24 - Best Overall Space Vessel
Day 25 - Favorite Discovery Episode
Day 26 - Planet You Would Most Like To Visit
Day 27 - Character You Would Date
Day 28 - Name Your Own Starship
Day 29 - Favorite Trek Quote
Day 30 - Favorite Trek Series