Krea and Bindo for sure. Their take on the force and the way your perception of and relationship to the force impacted ur character (and the world around u) in both games was pretty compelling.
I could give two farts about lightsabers or ewoks, personally. But those games made me actually appreciate the Star Wars universe. I dig a good story with memorable dialogue and characters. Both games delivered that, I think.
But that is just what I like. I don’t really know what makes a game sell (back to the topic). I imagine marketing is key. Plenty of subpar games have great marketing and get that first initial rush of buyers who want the next new thing (eg CP77, Fallout 76). I am interested to see BG3s initial sales versus longevity of purchases. Of course, the latter may be linked to mod capabilities and large communities (eg Skyrim).