I second:
Bone
"Herobear and the Kid" by Mike Kunkel (Astonish)
In addition to those, I own, have read, and enjoyed all the following:
"Leave It to Chance" James Robinson and Paul Smith (Homage)
"Scary Godmother" Jill Thompson (Sirius)
"Owly: Flying Lessons" (or any of the Owly comics actually), by Andy Runton (Top Shelf)
"Spiral-Bound" by Aaron Renier (Top Shelf)
"Tommysaurus Rex" by Doug TenNapel (Image)
"Little Lit: It Was a Dark and Silly Night" edited by Art Spiegelman and Francoise Mouly (HarperCollins)
"Pinky & Stinky" by James Kochalka (Top Shelf)
I also think
Thieves & Kings might be appropriate, and is quite good. Probably that, Bone, and Leave it to Chance are the closest to the genre you are looking for.