The skyscraper tower

  Minecraft has a lack of dungeons, either for the overworld, caves and the other two dimensions, this dungeon would be an extremelly high tower spawned in plain biomes, which each floor containing different challenges, being either parkour, puzzles or fight against a group of hostile creatures, and the whole tower has many loot making it worth to adventure inside it, they don't have to add exclusive creatures, blocks, boss or items for this dungeon, all the minecraft community want is more dungeons, no matter if they're exclusive or not, it's really important for the exploring and adventuring part of the game to have more dungeons than minecraft currently has.
  The top of the tower would be open to the sky, and it also has phantom spawners, making those mobs spawn in another way that doesn't depend of the much we slept, as this mob was kinda of a bait, most of the community voted for it because they thought that it would be an awesome flying monster and threat, but instead it's just an annoying swarm thing that only spawns if we don't get enough sleep, i think that if there were a dungeon which contain their spawners it would make it way better, they could even contribute to insomnia with their attacks, and that's exacly the point of this post.