Grand Unifying Guesses/Dark World

The following are all the same place:

• Hell, obviously.
• The Warp
• Hueco Mundo
• Minusland
• The Minus World
• The alternate hotel from Trilby's Notes, also known as the Realm of Magick/Realm of Chzo
• Yami-gaia
• Shinigami's World
• The Demon World
• The Twilight
• Times Square during the 1970s and 1980s
• The dark side of Imaginationland
• The Ghost Zone
• The Spirit World
• The Spirit World
• The Phantom Zone
• The Phantom Zone, again
• Dollurh
• The Dark World
  • The Gap Between Dimensions, where Phantom Ganon was sent.
• The Home For Infinite Losers
• This place has a lower vibe than the Realground
• The Netherworld
• The Shadow Realm
• The Shadowlands
• Ghost World in the 2009 game
• The Dungeon Dimensions
• Todash
  • But, Todash isn't a world while the places listed above are.
• Zimmy's world
• A number of places in the Digimon franchise, including the Dark Area, Dagomon's Ocean, and the dimension in which the D-Reaper evolved.
• London Below
• The Dark Hour
• The Otherworld/Midnight Channel
• |The Otherworld
• Otherworld and its various layers
• The Otherworld.
• The Dark Realm
• The Spectral Realm
• The Realm of Darkness
• Valhalla
• The Netherrealm
• Hotel California
• The Barren Landscape of the Demon-Beasts.
• The Boundary
• Shadowfell, Shadowdark, Darkbad, Shadow Shadow Bo Badow, Double Hell and Scarytown.
• And all of these places are 'Soft Places' as described in The Sandman, where the boundries between reality and the Dreaming are weak.