Aver: By non-fantasy I mean something in more modern times or in a future. Also, I already checked all RPGs on GOG :).
Btw. I doesn't have to be exactly RPG. It may be anything with dialog system and moral choices in it.
This may look as a strange suggestion, but if you don't mind space shooters and interactive movies, take a look at Wing Commander III. It has a great story, there's a lot of character interation, and moral and dialog choices are there, even if somewhat limited compared to classic rpgs. On the other hand, you can also influence the plot and get different dialogue options simply by winning or losing missions.
And also, +1 for the first Kotor. If you liked ME, they share many of their core elements.