Leonard Hofstadter
Dr. Sheldon Cooper, Leonard Hofstadter’s best friend, was also an experimental physicist, and the two of them lived together in the same apartment. In the series, the developing romance between Leonard and his next-door neighbor, Penny, served as a driving force. He takes his name from actor Sheldon Leonard and physicist Robert Hofstadter, both of whom were nominated for the Nobel Prize in Physics.
Played By Johnny Galecki
He was similarly yanked from the Roseanne-era show, but his performance on The Big Bang Theory garnered him multiple nods for Emmys and other awards. The Forbes magazine estimated that Galecki was the second highest-paid television actor in the world in 2018.