The Nightmare Before Christmas becuase I'm always surprised at how good it looks in 3D. Saw it twice in theatres in 3D and the Blu looks and sounds great.
Of the 3D Blu-rays I already own (I have some catching up to do!), and choosing only one, I'll have to award the honor to HOUSE OF WAX...which by the way, some friends are being treated to (at their own insistence) at a small gathering on Halloween.