Pretty much the only game(s) where I looked forward to reading. Check out the first one's gameplay to get a gist of the mechanics. The second expands on them but there's a good chance you'll have something spoiled. The first game explored "who am I?" and the second is "how did I get here?" - I think the slow reveal of the latter adds a lot to the game. I also think the collectibles (audio logs) aren't just achievement bait. They add a lot, too.
I'm not watching the trailer or clicking this link but I have no hesitation in preordering. I went into the second game blind wondering how the hell they could make a sequel...but they pulled it off. And although I didn't like the ending of the second game as much, I'm going in blind again.
All right that's enough gushing over a video game.