for me its eminem, my mom calls him a sexist, mean spirited, and homophobic assh*le.

Every band I listen to. Not only is the music a "raucous" but the actual members of the bands are all homocidal and suicidal.

back in the day, it was twisted sister that scared my parents.

although my parents never expressed their disgust, I know they didn't approve of most of my tunes, especially:
King Diamond
Slayer
Venom
Mercyful Fate
...and pretty much anything else that was heavy and satanic...

Celine Dion

Oh, you mean artists that are nightmares because their kids like them. I was thinking of artists that give ME nightmares.

I know this probably isn't what you meant, but my parents were more than a little concerned that I was listening to Johnny Mathis and Anne Murray when I was 12.

Honk!