Fought with this all last night, solutions that did not work for me:

installing directly to C: drive
running with admin rights
compatibility mode
updating a bink.dll
reinstalling video drivers
changing safemovie values
critical rebuild patch 1.69 from Bioware

What did work, and I hope works for everyone else:

ALT-CTRL-DEL and make sure the nwn and nwnmain exes are ended.

Go to your C: drive and in the top right type a3d.dll in the search box.
Attempt to delete every file that comes up. Some won't allow it, but the important file that is causing NWN to crash after splash will delete.

Launch NWN and be happy :)

Deleting this file (its an old sound driver for certain chipsets (even if you don't use that chipset)), is all I needed to do. I didn't have to change the install location, permissions, or run in any compatability mode.

Did you get and install the 1.69 critical rebuild patch from Bioware also?

That is probably the lone most important thing to get rid of problems...

Sure did, one of the first solutions i attempted talked about how the GOG version wasn't as up to date as it could have been, and needed the manual patch from bioware.

Simply forgot to list it in my solutions tried, I've updated it now. Thanks.

This absolutely solved all my problems