Now that the role has been cast in the upcoming movie, I would like to put forward an argument that Thor's villainous brother Loki, the God of Mischief, isn't all that bad.
Take this early apperance in Journey Into Mystery #88, for example. Loki comes down to Earth and starts "terrorizing" humanity by...
...turning everything into candy and ice cream.
...diffusing Soviet nuclear bombs.
In fact, the only remotely frightening thing that he does is turn a bunch of people into blank white versions of themselves:
But even that isn't so bad because he has no intention of leaving them that way:
I ask you, wouldn't you rather have this guy around than the one who hurls a giant hammer around and makes lightning strike everything?