Yes, Mario is evil. Just think about it - in the original Mario Bros. Bowser used his magic to transform the denizens of the Mushroom Kingdom into blocks - the very same blocks Mario so readily destroyed as he rummaged the countryside in search of cash and drugs. He also murdered absolute scores of Bowser's loyal troops - compare this to the "evil" Koopa King, who has never actually killed another person. Also, when he reached Bowsers lair, Mario had no qualms about disposing of the tyrant in the most gruesome way - by throwing him into the lava. In fact, in New Super Mario Bros. he even did a little dance and said "That's-a so nice!" after watching the flesh burn from the bones of his nemesis.
If that's not evil, frankly, I don't know what is.
