I own Morrowind, but don't own Neverwinter nights.
On Morrowind you will see everything bar the special water effects. On Neverwinter nights - you should see most things, but you'll be better waiting for someone elses opinion on that.
I was suggesting you purchase the games, see what you think of them, if you like them (and the graphics) keep them, if you don't then return them, no harm done.