Nilfgaard, and it has been my favourite since the time when Swim's dorfs dominated the meta in summer(?) 2017. I had a Reveal deck teched with anti-dorf cards, called Morvran's Anti Dwarves. It was great.
I like the heavy control aspect, and the general theme of being annoying by messing with opponents' strategies. The very same things that many hate about the faction.
There are also strategies like my old
swarm deck (RIP, I still miss you) that focus less on messing with opponents and more on generating boosting.
I also like its Leaders and their voicelines.