The Sandman was one of my first graphic novels and reading this a second time around does not fail me. There's a little horror, maybe a little sci fi and definitely a little fantasy. Neil Gaiman knows and enjoys his craft and introduced me to a new genre like I'd never been interested in before.
As well as the writing, I enjoyed the graphics and enjoy the mixture of artists involved, I believe some of these are introduced in other volumes. I love Gaimen's definitions of the character Dream and the introduction of Dream's sister, Death.
Please read this, especially if you aren't into graphic novels or this fanstasy/ sci fi/ horror genre. You may find yourself a changed person.