I don't know about you, but I'm a big fan of Creator Owned Comic Books.
I love the Big 2 but the diversity that can be found in comics by other publishers is what makes the medium special. There are a ton of "flash-in-the-pans", some solid series and then there are those few characters that hook themselves into the mainstream.
For the purpose of this discussion I'm focusing on individual characters rather than shared worlds type of series like Astro City, Strangers in Paradise, League of Extraordinary Gentlemen, Sin City, etc.
By no means is this list complete, I tried to select the most visible and prolific of characters. It is a major accomplishment for a non-Marvel/DC book to publish 100 issues and each of these characters have done that and more. I'm sure I have left some out and please feel free to remind me of whom I have neglected.Spawn
Demonspawn struggling to find his balance in the world.
Like him or not, Spawn and McFarlane have proved to be powerful entities in their respective genres.Cerebus
The eponymous aardvark whose exploits were certainly a thing of legend. 300 issues of Awesome.Bone
This is an insidiously fascinating story. Leave your preconceptions at the door. Hellboy
Quite iconic and made the transition to the big screen. Some of the best supporting characters in the milieu. Grendel
The manifestation of evil made corporeal. But sometimes he/she/it is not so evil. Incredibly fascinating study of human frailties, seductions and moral struggle.Madman
Surreal adventures of an undead superhero. Very overlooked but vastly entertaining, do yourself a favor and pick some of these up.Groo
The slow of mind barbarian that everyone loves to hate. First of all, never get on a ship with him. Second, whether you are a friend or an enemy - stay as far away from Groo as possible. Third, I forget what third is but I have a question: What is mulch? And who's slow of mind?Savage Dragon
Saurian super-cop in a futuristic world. One of the longest running creator owned series and it is still coming out!Anyone Else?
I know I have missed some. I have a few in mind myself. Who do you think should be included?