Galecki played Leonard Hofstadter in the CBS sitcom "The Big Bang Theory", which ran from 2007 to 2019 and was, for most of its run, among the top three most popular television comedies in the US. Galecki was originally asked to play the role of Sheldon Cooper, but he felt he was better suited for the role of Leonard, and Sheldon's role was eventually given to Jim Parsons. During the show's run, two of Galecki's former "Roseanne" co-stars appeared on the show: Sara Gilbert (as Leslie Winkle, Leonard's colleague) and Laurie Metcalf (as Mary Cooper, Sheldon's mother). Galecki is a cellist, a talent that was used on the show. Until 2013, Galecki and his "Big Bang" co-stars Kaley Cuoco and Jim Parsons each earned US$325,000 per episode. By 2014, the three were earning US$1 million per episode.