I'm a new member.
I wanted to reply to this post, cuz I have played NWN several times, and it still remains one of my favorites.
But anyways, onto your question.
In my opinion, the Diamond Edition is the BEST one to get right now.
This great set includes the original game, BOTH expansions, and also the user created mod/expansion King Maker, which until now had only been available as a download from the NWN sites.
This is the one that I want, even though I have the original game and both expansions, I still want this Diamond Edition.
Hope that helps you....see ya