George Thorogood's "Bad to the Bone" is a song sung from the point of view of someone who really likes being bad. (And is often played in movies when actual Card Carrying Villains appear.)
Denis Leary's song "Asshole" describes someone who delights in making other people miserable, and proudly proclaims himself to be the "world's biggest asshole". He does such things as driving really slowly in the ultra-fast lane, and intentionally parking in spots for handicapped people when said people need the parking spots.
The Diamond Head song "Am I Evil?". The answer is, unsurprisingly, "Yes I am!".