I know absolutely nothing about comics or graphic novels. But the Musuem of Contemporary Art in Chicago has an exhibit on Chris Ware right now, whose most well known for his 'Jimmy Corigan, The Smartest Kid on Earth' grapic novel, which is really fantastic. That's all I've really been exposed to, but it's pretty engaging.
Here's a link discussing the exhibition and Ware's work.
http://www.avclub.com/content/node/48760