Best “mystery box” shows?

As much as people seem to hate Lost nowadays, the first 3-4 seasons completely sucked me in. And it seems like a LOT of newer shows, especially on the streaming services, have been incorporating “mystery box” elements.

A couple that come to mind for me:

- The 100. I thought the first 3-4 seasons did a fantastic job of both answering questions and creating new ones. Eventually the whole “violence begets violence” trope gets old and the show kind of runs out of material to explore, though.

- The Leftovers. The recent thread about this show is what made me start thinking about the genre. The Leftovers is a true mystery box in just about every way, which makes sense with Damon Lindelof as showrunner. To me it’s an example of what Lost could have been if they hadn’t felt the need to answer every question in the later seasons.

- Mr. Robot. Fantastic in so many ways. I didn’t love the ending, but I didn’t hate it either. But man, the storytelling along the way, cinematography, soundtrack, and acting are really good.

So what are your favorite mystery box shows, or favorite shows that have some of those elements?