I don't like listen to nor like Lady Gaga but I think she deserves at least some credit. She writes her own music (albeit, it's not very good) and produces them. She even writes music for other artists as well. That's a hell of a lot more than most mainstream artists can take credit for nowadays. On top of that, she's a trendsetter and businesswoman. Again, I don't like Lady Gaga but I'll give props where props are due.
On the other hand, Katy Perry doesn't write nor produce her own music. She most certainly deserves to be in this thread.