I don't know much about graphic novels myself. I cut my teeth on ElfQuest and Heavy Metal back in the 80s, followed by V for Vendetta and then the Sandman Comics. Before all that? It was nothing but comics like Sgt. Rock, The Unknown Soldier, and Weird War Tales.
If you like folklore AND graphic novels, however, I do heartily recommend Charles Vess'
The Book of Ballads. It's some of the Child Ballads scripted by the likes of Neil Gaiman, Emma Bull, and Charles de Lint, and illustrated by Vess.
For regular reading, I still can not push Terri Windling's Borderlands/Bordertown anthologies enough. "Where elves meet rock and roll..."