On NWN, I actually liked the first expansion better than the second. It was nothing grand but well written and manageable. (I actually finished it, unlike the official campaign and HoTU). Deekin and the Dragon were very entertaining and paladins got lots of nice stuff.

The original campaign is pretty awful, but has its moments. The Chapter 1 finale was a blast and Charwood was as good a sidequest as any in a CRPG IMO.

But yes, nowadays, I am sure you can pick up NWN and the expansions as a well priced bundle. The extral cost over just NWN is probably marginal and the newer mods may well require the expansions.