I did all four campaigns several times.
Venthyr is still my favorite I’d say, but I’m slightly biased since the zone and everything there is the one I like the most.
Venthyr, Necro and Kyrian all have a continuous storyline, which is more to my liking than the Night Fae one, which alternates between three storylines and none of them comes to an actually satisfying end.
Even though someone else disliked exactly that fact, I also do prefer the first three campaigns, because they interact with each other. Yes, this results in overlapping chapter quests, but it also helps to see the Shadowlands more like a realm that belongs togeather.
But yes, even though I like the Necro campaing from a storyline perspective, it’s also the one who has the most overlaps with other campaigns in my eyes, since apart from the first two chapters (or chapter 3 + 4 if you look at the questlog) more or less all other chapters are either an overlap with the Kyrian or the Venthyr campaign.
From the actual story content I disliked Kyrian and Night Fae, because the events and the behaviour of the characters (Uther, Archon, Kleia / Tyrande, Drust) didn’t make much sense to me. Venthyr and Necro work far better in that regard.
Here’s btw a thread where we discussed the campaigns earlier: Campaign finales... (spoilers if you have not played them yet!)