Who's the PERFECT character for a story in your opinion?

Not from all stories you've read, could be from a specific story. And could be the hero or a villain or some second choices who made you cry.

In short, a character that made the reading of the story more enjoyable for you.

Was reading RIM(Regressor Instruction Manual) and i realised that pretty much the only reason i read the novel was that even if the mc was being an asshole, he was self aware and most of his actions were pretty justified(most i mean, not all, in some he did deserve the karma he got), the only reason he was an asshole was because of his twisted way of doing things.