TBBT's Bernadette And Amy Wouldn't Have Remained Friends If It Weren't For Penny

The Big Bang Theoryexcelled at showcasing an ensemble cast with niche interests and personalities. While the sitcom focused on a group of friends, it became clear in later seasons that two characters were only friends because they had to be: Amy Farrah Fowler (Mayim Bialik) and Bernadette Rostenkowski-Wolowitz (Melissa Rauch).