Most recently, Slay the Princess. It's a VN, and I typically do not play VNs, but wow. It's actually quite amazing and I can't actually tell you why because it'd spoil it.

I get pleasantly surprised all the time though, since I like to use a randomizer to choose my next game sometimes. I think one of the other experiences was the Rusty Lake games. I got them in a bundle and since it was a puzzler, I had my friend join me in comms and it was... very strange. But we will use references from those games as insider nods to one another.