I haven't printed out and tested a single expansion yet. But I have dabbled with some digitally testing them when I code etc.
Today I have no means of printing out any tiles, but rest assure, next year I will make this happen. Just lacking blank tiles.
As to what expansion I like in general, it's usually those that have extra tiles. I like less wooden figures, or extra rules that takes time to learn.
One good example is the nature disaster idea, which could open up a whole lotta fun and crazyness. Sort of an amped version of the Dragon.
The lake. Also one I like very much.
Come to think of it, maybe I like fan expansions that have a visual concept art to make beautiful scenery rather than playing the games.