Despite the fact that I only read "Preludes and Nocturnes" I still think Sandman is one of the best comics ever. The writing is always phenomenal but yes, the art quality varies. I have a feeling, though, that the artists can draw better.
I especially loved the last comic in "Prelude and Nocturnes".
! Death rules. Period. And indeed, that particular episode (chapter?) is great. I'll have to hunt down those spinoffs featuring Death one of these days.
