These are a few of my favorite GNs
I'm often asked for graphic novel recommendations, so here's a quick list, not by any means all-inclusive.

Recent Books & Authors That Knocked My Socks Off:

The Rabbi's Cat, Klezmer, and other titles by Joann Sfar
The Photographer, Alan's War, and The Professor's Daughter by Emmanuel Guibert
Curses, the CCS catalog, and other titles by Kevin Huizenga
Satchel Paige: Striking Out Jim Crow, by James Sturm and Rich Tomasso
Scott Pilgrim, by Bryan Lee O'Malley
The Arrival, and other titles by Shaun Tan
Exit Wounds, and other titles by Rutu Modan
Three Shadows, by Cyril Pedrosa
Skim, by Mariko and Jillian Tamaki
American Born Chinese, by Gene Yang
Five is the Perfect Number, and other titles by Igort

Older Books That Inspired Me

Tintin, by Herge
Asterix, by Goscinny and Uderzo
Ethel and Ernest, by Raymond Briggs
La Mouche, Dungeon, and other titles by Lewis Trondheim
The Dormant Beast, and other titles by Enki Bilal
Le Cheval Sans Tet, anthology by L'Association (French)
Dr. Jekyll & Mister Hyde, and other titles by Lorenzo Mattoti
The Tower, and other titles by Francois Schuiten
Appleseed, and other titles by Masamune Shirow.
Kane, by Paul Grist
The System, Stripped, and other titles by Peter Kuper
Onion Jack, by Joel Priddy (Best American Comics 2006)
Jimmy Corrigan: Smartest Kid on Earth, and other titles by Chris Ware
Maus, by Art Spiegelman
Persepolis, by Marjane Satrapi
Jar of Fools, and Berlin, by Jason Lutes
The Dark Knight, 300, Sin City, and other titles by Frank Miller. Elektra:Assassin by Miller and Sienckiewicz
Moby Dick, Stray Toasters, and other titles by Bill Sienckiewicz
Cerebus: High Society, by Dave Sim
The Tale of One Bad Rat, by Bryan Talbot
Why I Hate Saturn, and The Cowboy Wally Show, by Kyle Baker
Hellboy, and other titles by Mike Mignola
Watchmen, The League of Extraordinary Gentlemen, and other titles written by Alan Moore
Understanding Comics, Making Comics, and various Scott McCloud thought experiments on www.scottmccloud.com
(see Scott's TED talk)
The Airtight Garage, 100 days in the Desert, and other titles by Moebius
Escapo, THB, and other titles by Paul Pope