for light fantasy suitable for minors but still immensely enjoyable for adults - Bone by Jeff Smith
for monster-themed humor/weirdness - Boneyard by Richard Moore
for fucked up general bad-assedness and an awesome mindblowing read - PREACHER by Garth Ennis, and to a lesser but still great degree - Watchmen by Alan Moore
for superhero stuff with a twist - Top 10 by Alan Moore, Astro City by Kurt Busiek
for an awesome take on traditional fables - Fables by Bill Willingham
There are others, but those stand out in my mind right now, especially Preacher, go read that if nothing else. I'm not really impressed with too much of the mainstream Marvel and DC stuff, but I did like the original Kingdom Come storyline written by Mark Waid and painted by Alex Ross. The story was good, but the art REALLY stood out.