I watched the TV show before I read all the books, but I was hooked by the same moments that I think you’re talking about.
One of the things I hate the most about books and movies is that naive characters almost never face any consequences for their reliance on ideals and failure to think those ideas through. That lead-with-your-gut style leadership that always works in story land almost never works in real life. I love GRRM for swinging a greatsword right through that trope.
The first Miles Vorkosigan story I read was The Mountains of Mourning. Miles has gone to the back country to investigate a murder, which someone is trying to convince him never happened. Miles listens intently to what the man says. “I begin to see,” Miles’ voice was mild, encouraging. Karal brightened slightly…and then Miles lets him have it. " I begin to see why Harra Csurik found it necessary to walk four days to get an unbiased hearing. ‘You think.’ ‘You believe.’ ‘Who knows what?’ Not you, it appears."
This story takes place on another planet, in the Dendarii mountains. It’s why I’m Dendarii Dame.
In my opinion, nothing else in The Hunger Games matched the brilliance of that passage. It actually left me somewhat disappointed in the rest of the book.
My contribution to the thread is Stephen King’s IT. I read it at what was probably an inappropriately young age, when I was 9 or so years old. There’s a part in it when King talks about how kids exist below the sightline of adults, and as long as you’re below that line, you can get away with pretty much anything, because adults just aren’t aware of you in the same way they’re aware of other grownups. I remember so clearly thinking, “this guy gets what it’s like to be a kid.”
I didn’t read them in order, so for me it was: “Jack you have debauched my sloth!”
“But geography is only physics slowed down and with a few trees stuck on it…” Terry Pratchett’s Feet of Clay, the first Discworld novel I read.