Unpopular games you feel are the Apex of a genre

[Mar1217]

I'd say it's a toss up between 999: 9 Persons, 9 Doors, 9 Hours (Zero Escape 1) or Virtue's Last Reward (Zero Escape 2) in the Adventure/Puzzle genre.
Tightest interwoven narratives created in the history of the medium + great "escape rooms" puzzles to figure out.