Journey to the Membranous Labyrinth
I find that a good dungeon comes from an act of inspiration, drawn from the persistent ideas that I just can't otherwise get out of my head. I never expected to find a literal expression of this idea, but I have.
Squidman's Membranous Parasitic Dungeon is a micro dungeon literally inspired by an infection of the membranous labyrinth the Squidman carries in his own head (don't worry, I think that's just health-mage speak for an ear infection). I am terribly jealous.
The Labyrinth is a very serviceable little dungeon with a good hook to fit it into your campaign and the potential to bring an interesting change to that campaign in the future. It has a mix of encounters which can be approached in a number of different ways. There's also lots of scope for creepy mystery and suspense.