The Big Bang Theory finale may have failed Sheldon's true soulmate, Leonard. The show's core relationship was always between the boys of Apartment 4A, and it would have been more satisfying to see Sheldon and Leonard team up for success in their field of physics. While Sheldon and Amy winning the Nobel Prize was a great moment, it didn't feel as natural as seeing the original duo bond one-on-one. Leonard had been Sheldon's closest friend long before Amy came along, and the overall series' story hinged on their relationship. Bringing the focus back on these two primary characters would have made for a better ending.
