Super Mario Galaxy - The Underground Ghost Ship

Deep Dark Galaxy - Mission 1
The Underground Ghost Ship

Everyone forgets about the Deep Dark Galaxy. I guess it's because there really isn't a unifying theme across the Galaxy. I mean...look at it! There's a deflating Gateway Galaxy home planet.

By the way, is it a coincidence that where the fourth dungeon of Zelda: Phantom Hourglass is a ghost ship, that the fourth stage in Sonic Rush Adventure is the Haunted Ship Zone? And now Mario wants in.