Good thread, SFG.
One of the best, best manga series ever created is Goseki Kojima's "Lone Wolf and Cub" series. I started reading the books when I was just a mite living in China, but I know it has recently become available in the States. Uncharacteristically for manga, the writing is awesome, and Daigoro is just so damn cute! Any fan of manga knows this series, as it is a classic.
And my favourite comic is "Jar of Fools", by Jason Lutes. I first read it when I was 14 or so, and it still remains as beautiful and complex and heartwrenching. But a lot of Lutes' stuff is good - like his "Berlin" series.
What else....hmmm, I think I mentioned "Palestine" and "Safe Area Gorazde" a long time ago in another thread here. By Joe Sacco. And of course, everybody mentions Spiegelman's "Maus" anyway so there's no need to go into it.
Ooh, I know! This one doesn't really count 'cause it's not a comic but I just looooved the Vampire Hunter D novels. Had such a crush on D the way Yoshitaka Amano drew him. And its manga film "Vampire Hunter D: Bloodlust" is pretty good, too.