Neverwinter nights wasn't for me... after all these talks about beautiful 3d graphics and many other features, NWN was really dissapointing game to me after baldur's gate 2. Graphics too repetitive, battles too easy, it reminded Diablo at some points.
Divine Divinity on other hand is way more interesting, just it got REALLY boring after becoming divine one, i was working to fininsh that game. Although there were many quests that made me laugh, so overall it was ok, i just missed some company besides me, that was cheering me most of the time in baldur's gate 2. But NWN doesn't give you companions either, just 1 mercenary, that isn't interested in advewnturing, it seems, just doing his/her job.
So DD is better, but baldur's gate 2 is still something to reach for both these games, DD should get a bit more complicated fighting system, hit, hit, kill, be it spell, arrow or sword is still the same.