Sacred Haven of Debauchery

Plesik, please tell me, which Neverwinter Nights campaign is worse? The first or the second?

It depends on which campaign you're talking about. So:
The original Neverwinter Nights campaign versus the second Neverwinter Nights campaign:
Advantages of the first campaign:
1) Atmosphere of Forgotten Realms
2) Companions are not annoying (except for their stupid AI)
3) Canon
Advantages of the second:
1) The companions' personalities are more apparent, but because of that, you want to strangle half of them.
2) More dialogues, but they are (not all) unnecessarily drawn out or just boring.
But the second one has some serious drawbacks:
1) Lack of Forgotten Realms atmosphere
2) The plot is stupid, but unlike the first part, it is not just non-canonical, but contradicts the world, there are many inconsistencies.

So, for me, as a fan of Forgotten Realms, the second campaign is terrible.
As for the expansions, here's the situation:
The Storms campaign is the worst, followed by Underdark, then Mask of the Betrayer, and then Hordes of the Underdark.