Wouldn't that depend on the purpuose of the character? Is it even a character created for a story? Is it the main character, a support character? A character is a tool, you use it to tell a story, make a point, convey and emotion and a whole lot of other things. It is what you do with the character that matters not the character itself. Or perhaps I just misunderstood this whole OC thing?
Interesting, ability to relate to or aspire towards.
Relevancy to the story. A character is only a plot device when you get down to it.
As Narutokunobsessed said a lot of stories can have bland boring character but if the story is plot driven. There are three types of stories. Stories about people, stories about places, and stories about events. Macbeth is about a person. Harry Potter is about a place. The book of Matthew is about an event. A character is only as good as they are useful to the story.
Forget names and sad backgrounds(Which in many cases could be the plot of a good comic), or over-powered abilites, a good character is someone we can relate to, who are just like you and me, have our doubts, our strenghts and weakneses, do fail sometimes and win. You don't call it a "main-character" for no reason.
A character that has balanced traits, both good and bad. The personality reflects the kind of character they are and is shaped by their environment (or genetic factors), much like people and other creatures.