The term 'long-running show' can be summarized by three popular shows: 'SAGA', 'HIT', and 'GREASE'. 'SAGA' is a Canadian drama television series that aired for six seasons from 2011 to 2018. 'HIT' is a British musical comedy-drama television series that aired for two seasons from 2017 to 2019. 'GREASE' is a musical romantic comedy film released in 1978, which was later adapted into a Broadway musical and a sequel film. All three of these shows have been popular for many years and are considered long-running shows.