What makes a Character Evil? What makes them Good?

And what makes them interesting?

Today I want to know what, for you, makes a character good, evil, or interesting. And when I say good I mean morally on the lighter side of things while for evil I mean morally in the black. Interesting is its own category.

For me, a character that is good is one that questions their own moral compass. They're never 100% certain they completely in the right and so pay special attention to the people around them, seeing the effects of their decisions and then either continuing on that path if they notice positive change. If their decision had a negative impact, then they'll do everything in their power to correct their mistake.
An evil character might commit heinous acts of meanness, but what makes them definitely disturbing [to me] is their unquestioning loyalty to their own creed or goal. Faith to a fault; reality has no bearing on their personal outlook and the impact of their decisions on others is either ignored or rationalized.
An interesting character is one that balances these traits. They might have a personal creed they'll adhere to, but they must question that unwavering faith in their philosophy as the story goes on. That moment when they come out of their hidey hole of personal comforts, look out at the vast swath of destruction they have witnessed or created, and go "oh, shit." THAT makes me interested in a character.

For example, if we've got a character that's so determined to prevent a terrorist attack that she resorts to torturing an inmate for information, this is an evil act. She's so certain of a pressing need that she'll break moral codes to get what she wants. But what would make her evil [for me] is whether the act of torturing someone made her sit and think and question herself OR if she simply waved off the act as "necessary roughness" and continued on unaffected.
Making it even more interesting would be having the information received via that torture be wrong, and as a result of that torture resources meant to save lives are squandered and people killed regardless. The evil character has an "oh shit" moment.
OR if the information is true and lives ARE saved, the good character faces a personal conundrum. Did the ends justify the means? If this happens again, can you just keep hurting people until you save enough people to make up for it? The good character is concerned with becoming evil and wondering which lines they've crossed. They're determined to do something to atone for this behavior.
Both options make a character interesting for me.

For you, my watchers, how would you answer this question? Feel free to answer also what makes a character good or evil in a less philosophical sense as well. Kicking puppies, killing children, and raping babies are all evil acts. What then are positive acts? And why do you find a good or evil character interesting? Is evil interesting simply for being taboo? Can good be interesting? Can you think of specific characters that lay along the moral spectrum which you liked or disliked and why?