Comic-book lovers, it's time to cast off the shame

I'd second Walking Dead, although it's a very bleak book. But Chew, which IIRC is about a cannibal, probably isn't the best introductory book for people wanting to get into comics.

I'd also add as a good non-superhero book "The Unwritten" by Mike Carey and Peter Gross, which follows the adventures of a guy who was the basis for a Harry Potter-esque series of hit children's books and who now, as an adult, discovers that some of it might not be so fictional. It's an interesting meditation on topics like fame, the connection, the nature of fiction, and the connection between culturally created narratives and reality.