Going to avoid all of the standard top 40 bands, everybody knows they suck. Even people who listen to them know deep down that they are listening to the musical equivalent of junk food, empty musical calories. Only one I'll mention by name is the Black Eyed Peas, who are SO bad, that they are like poisoned junk food.
No, instead, I'm going to focus on DJ's. There are a LOT of bad ones nowadays. Here is a list of people who deserve to be punched square in the face should I ever have the bad fortune of meeting them face to face:
Deadmau5
Tiesto
Skrillex
David Guetta (ESPECIALLY you, Guetta, **** you.)
This brostep crap in general has got to be stopped for the good of humanity but these jerks were the first names to spring to mind. I hope no advanced alien races are monitoring our airwaves and pick up on these guys, because I'm pretty sure they would constitute grounds for immediate planetary bombardment.