The prologue of NWN and first chapter are the only parts I didn't like much, though the end of chapter 1 was really good.
I loved the whole zombies taking over Neverwinter theme. It's ZOMBIES! Need I say more???
It frickin' ruled!!!!

In chapter 2 the overrun city fof Luskan was so-so, but it picked up after it. Hunting for the "Words of Power" in chapter 3 was cool, although I agree the whole ancient race of lizard people was a little far-fetched, but the adventure was great.
I didn't like the whole ancient race thing. A lot of those quests were linear and not many ways to finish them. Pretty linear and cookbook.
Many of it was far-fetched, which is okay, since it's a "fantasy" game, but I found a lot of that "anceint race" storyline was poorly developed and felt quite rushed. Most of the decent stuff in Chaps 2 and 3 were the side quests.
I always liked the whole storyline w/ Fenthick, Aribeth, and the leaders of Neverwinter. Personally, I thought that should've been the focus of the game, since that story seemed very well developed.
The conclusion to the game was great, I loved the final confrontation.
The Final Chapter battles....
[spoiler]...The battles w/ Aribeth, the two dragons, and then Morag were just great battles.
I wish the rest of NWN was *that* good, myself.
I wish there were more quests as cool w/ as many finishing pathways as Chap 3's "Trial" sidequest, too....[/spoiler]