Not a big comics or graphic novel fan but I heard so much about Here by Richard McGuire that I ordered it. "Read" it on Friday evening (vaked) and it blew me away. Maybe not quite as awesome second time round in an unaltered state but a nice book, a good experience.
BTW- if you want to try comic-based graphic novels to see if you like the genre, probably the best ones to start with, IMHO, are Alan Moore's. Especially Batman: The Killing Joke (can get that for less than $10 new on amazon -
http://smile.amazon.com/Batman-Kill...d=1425843117&sr=1-1&keywords=the+killing+joke) and everybody knows who Batman and the Joker are, so you don't need to know comics to get it.
Then, if you like that, Moore's Watchmen. More expensive, longer, and more convoluted. But head-and-shoulders above the movie, and again, no knowledge of comic book continuity needed.
If you like those, you can then try some of the legendary ones that do connect directly with comics, like Stan Lee and Jack Kirby's 1978 Silver Surfer graphic novel or Lee and Moebius' Silver Surfer. Then I'd recommend anything by Jim Starlin, one of the few people who both writes and does the art, and writes both comics and graphic novels. He's a personal favorite, and is becoming more and more popular- Thanos, the bad guy from Guardians of the Galaxy and at least two upcoming Avengers movies, is his creation (and the subject of most of his graphic novels). Plus his Dreadstar comics and graphic novels are being developed for television.
For great graphic novels that have no relation to comics at all, check out Art Spiegelman's Maus (about the Holocaust, but with mice as Jews and cats as Nazis, heavy but brilliant), or Will Eisner's Contract with God, considered by some to be the first graphic novel, about life in a Bronx tenement (based on Eisner's childhood).