The attention to detail, the different ways to win battles, the depths of the NPCs. I think this is the best RPG since Dragon Age Origins. I cannot say enough good things about Baldur's Gate 3. I think it deserves some kind of Oscar.
I spent my youth playing old isometric games that had levels of interaction that allowed me to control how the story plays out and they (mostly) only stood up due to my age and lack of creativity as a child.
Event with the higher expectations of adulthood, playing this game brings that feeling back and holds it for longer than those games of my childhood.