7. Mariah Carey and Nicki Minaj
In 2013, Mariah Carey and Nicki Minaj were both judges on American Idol. They never worked well together. They had expletive-filled fights from time to time. No one could fathom why they hated each other so much. At one point, though, Nicki revealed in an interview that while she considered Mariah a true legend, she believed that she was trying to get her bumped off the panel.