Love & Rockets (everything but especially the original series of oversize comix pamphlets, which you still come across in older comix shops sometimes) by Los Bros Hernandez -- This is the Bible, or the Koran. I would suicide-bomb for it.
Epileptic by David B. -- There's not a whole lot to the dialogue + captions, but this is a warm-blooded KILLER if you are PAYING ATTENTION to its SIGN LANGUAGE.
Gemma Bovery by Posy Simmonds -- the TRUTH about MEN expressed in a breezy and un-neurotic style
Palestine by Joe Sacco -- Nobody can put you inside a physical room quite like Joe Sacco can.
Storeyville by Frank Santoro -- It REDEFINED colour and atmosphere for me and reinforced some FEELINGS I've long had about the nature of friendship.
Rubber Blanket by David Mazzucchelli -- Best "loose" cartooning style I've seen, and his story about getting confused between Map and Territory tends to come back on you like bad acid but in a good way.
Ganges by Kevin Huizenga -- In a lot of ways, this is an extension of Mazzucchelli's discursive voice -- is K.H. a fan? -- except transplanted into a regular-looking guy whose face suggests he escaped from Ernie Bushmiller's universe. Now he lives in a peaceful, boring, early-21st-century suburban setting, and wrings magick from it. Glenn Ganges is America's foremost suburban sorcerer ...
Alec by Eddie Campbell -- ... and Campbell's alter ego Alec MacGarry might be the top discursive sorcerer for the rest of the English-speaking world. I really prefer Campbell's intoxicated/intoxicating essays in Alec and Bacchus to his more tightly-structured work with Alan Moore in From Hell, but it's ALL magick and all genius.
Promethea by Alan Moore and J.H. Williams III -- This is the nerdiest choice on here by far, but Williams' cartooning is too deLIGHTful to ignore or deny. Probably not as much of a page-turner as Watchmen and def not as much of a tear-jerker as V for Vendetta, but far trippier than either, and dang! every page is full of grace and sign language.
Kings in Disguise by James Vance and Dan Burr -- Perhaps the best John Cassavetes movie in comix (if JC did period pieces) and one of the v. few successful attempts at unadorned naturalism in an extended comix narrative (Jason Lutes' Berlin also comes to mind, but he's not done yet.).
Ghost World by Daniel Clowes -- It seems that 99 percent of my all-time favourite comix are about friendship in one way or another. Ghost World might be a perfect distillation of the good qualities of all of them -- mysterious, sad, comforting, comfortable, strange, wholehearted, and hilarious. DON'T try to talk to me about the movie, and don't try to talk to me about Adrian Tomine, as I have no use for either of those things.
Cerebus by Dave Sim -- I don't even try recommending this to people anymore, as it's 6000 pages long, and its latter half is encumbered by an increasingly unsubtle load of Mr Sim's politics, most infamously his attitudes toward women. Still, for world-building in comix, Dave Sim and his collaborator Gerhard are absolutely the sticker Dwight Howard put on the glass when he did that dunk in the dunk contest! FURTHERMORE a lot of "lesser" cartoonists could learn a lot by paying attention to Sim's characters' facial expressions and body language. He's a master, and I give him his props.
Binky Brown Meets th Holy Virgin Mary by Justin Green -- the TRUTH about MEN, and the most neurotic comix story in comix history thus far (which is saying a lot in a field crowded with the likes of Chris Ware, Robert Crumb, Charles Schulz, Maria Sputnik, anybody Japanese, etc., etc., etc., etc.)
The Rabbi's Cat by Joann Sfar -- If I say the word discursive one more time in this post I owe you a million dollars, but here is J. Sfar working in an easy, rambling style as you sit -- elbow on knee, chin on palm -- listening and smote. Motherfucker has the market CORNERED on talking cats, damn him!
Black Hole by Charles Burns -- the emperor of creepy
Hicksville by Dylan Horrocks -- All right, it's comix about comix, so I don't talk about it to people outside the fraternity/sorority; but it's a genius world, and not a day goes by when I don't want to live there.
"So yo then man what's your story?"