Betty White and Bea Arthur
A lot of Golden Girls fans have no idea that Betty White and Bea Arthur had a tumultuous relationship. Luckily, the show itself never suffered as a result of their ill feelings towards one another. They kept it pretty civil (for the most part).
Lauren Conrad and Audrina Patridge
Lauren Conrad and Audrina Patridge constantly made headlines as two best friends in MTV's reality show The Hills. No one is really sure what happened to their friendship... Not even Patridge. She once told CelebBuzz, "I don't really talk to Lauren or see her at all. I think there was a bit of a falling out."