I'm sure this is the same for many many fans but The Sandman Comics.
The original series itself is just superb (Dave's work just makes it too). The plot can never truly be grasped. Seriously, read it over and over and you will always find a little detail you didn't grasp before and fall in love with it again and again. He can capture little part of you that you may have though was silly or fanciful and make it glorious and sometimes a little frightening. The best thing about the Sandman is it doesn't stop! Little bits of it bleed out into all his other work and it seems never ending in awesome!
Many people have recently been complaining about Mr. Gaimens leap further into mainstream culture but I would like to say that this is not a bad thing because it means he gets more money to do more projects thus: more Gaimen.
Unlike many great artists I have faith that he will not sell out on his character or writing style because he is just that awesome.
How about all of you NerdFighters out there huh? (did we not freak out a little with joy when he did the the introductory hello on a vlog that time?)