The first time I hit character creation - realizing I am playing a top-down RPG but can have a character that can look like THAT - was incredible.
When I realized I can kill Astarion instead of being forced to continue the conversation after he had pulled a knife - it felt like a real D&D moment to me - freedom - instead of the typical videogame railroad.
Seconding Auntie Ethel quest's - there's a couple of amazing ones. E.G. when entire illusion of the swamp is dispelled in real time - that was a holy $%@t moment for me.
Using featherfall to traverse the outside of Mystra Cleric tower - it was one of those moments where I felt like this game was giving me a different RP experience even compared to some of my other favorite CRPGs.
Realizing how much interactions changed when I put on my drow disguise to get into the Goblin camp. Then learning about all the other reactivity (i.e. Shadowheart and your race, etc).
