The original campaign is a bit on the dull side, it's true. To be honest, I feel like the first chapter is the worst and it becomes a bit better later on, but it might not be worth your time anyway.
Shadows of Undertide, the first expansion pack, is, I think, better, but still nothing to write home about. Hordes of the Underdark, the second expansion, is the sequel to SoU and is actually very very nice.
NWN is not known for its official campaigns, though, but for community-made modules and campaigns. I'd say you drop the above-mentioned campaigns for now (you can come back to them later) and start with some gems (all of which you can download on Neverwinter Vault). Here are my suggestions:
-Darkness over Daggerford - it has a very strong Baldur's Gate feel to it and is generally very well done, so I'd suggest you try it if you say you were expecting too much of BG. It's won a prize for the best RPG mod of 2007 or 2006 if I recall correctly. It's not as long as a fully-fledged game, but not much shorter, really, 25-30 hours, I'd say.
-Prophet campaign - it's not set in Forgotten Realms and it's pretty linear (not many optional quests and stuff), but the atmosphere and the story is absolutely something you can't miss. It's one of my favorite story-based RPGs, if not THE favorite one. A good-aligned character is recommended, for the story makes the most sense in this case. It's easily 40-hour long.
Hah, looks like PeterScott made some of the same points as me, namely recommending the Prophet series and acknowledging the original campaign gets better later on. ;)
Anyway, once again, I'd say you start with the best NWN has to offer, which is custom content. Once you feel comfortable with the game and realize how good it can be, then you can try out the official campaigns. I think it would be unfair to start with them and put the game aside based on the experience you get with them, because NWN can be so much better than that.
Post edited February 03, 2017 by Taro94