Katherine Heigl and Shonda Rhimes
We all know that nobody likes Katherine Heigl. She's difficult to work with, rude, and selfish. Shonda Rhimes, writer and creator of Grey's Anatomy, probably regretted ever letting Heigl on the cast. Heigl publicly said that she was never given good material to work with and insinuated that Rhimes' writing was poor. Needless to say, there was no contract renewal and she was gone within a year and a half.
Rhimes, who is notably nice, did speak about this situation in an interview about her new show, Scandal. "I have a no a**holes policy on the set. There are no Heigls in this situation... I don't put up with bulls*** or nasty people. I don't have time for it." Shonda Rhimes rules all.