My rank of "evil" on Breaking Bad:
1. Gus - Killed and manipulated people around him, ect. Ordered a child to be killed.*
2. Walt - Killed, manipulated, and endangered multiple people including his family and a child, for selfish reasons.
3. Jesse - Murdered and attempted murder and selling Meth to addicts at support meetings, for no real reasons except for emotions and ego, probably.
4. Mike - Murdered multiple people based on his own reasons and from orders from Gus.
5. Saul - Working for and protecting drug dealers.
6. Skylar - Same as Saul basically.
7. Marie - Steals things for the lulz.
8. Hank - Beat up Jesse for being involved with the phone call that his wife was in a serious car wreck.
9. Walt Jr. - Eating more than his share of breakfast.
*This I'm sure of. Off topic, but consider the situation:
Gus at this time liked and respected Walt. Gus, on the other hand, didn't like Jesse. He was a drug addicted and unpredictable, emotional trainwreck. He was a liability and he was replaceable. Gus knew that if the child in question was murdered this would set Jesse off and he would get himself killed trying to take out Gus's street dealers. This would solve multiple problems at once. It would get rid of Jesse, and no one would be to blame for it but Jesse himself. It would get rid of the child who could have been a liability down the road, but it would also put Walt's mind to ease that no children wouldn't being used. And Walt being happy was important to Gus. Because, you see, Walt should of never known about the child. The chemist should never know what's happening on the street level - they don't need to know, it's not their business - and more than that, it would make the chemists more likely to quit knowing they're part of something causing horrible things that are happening (although, generally speaking, they already know they are part of horrible things, but when people hear specifics, it tugs on their emotions.)
Regardless, Walt screwed up Gus's plan and thus the great chess match commenced.