Three's Company pilot with different actors
The rather dreadful 1970s sitcom Three's Company adapted the UK sitcom Man About the House for American TV; it ran for eight seasons and was heavily syndicated through my whole childhood, and as with many people of my age, it lurks in my subconscious.
It turns out there was an unaired pilot that used some of the same cast, but a different writing team and a somewhat smarter brand of comedy, and it's surfaced on YouTube. Here's Wikipedia's description of that pilot:
The show was first penned by famed Broadway writer Peter Stone who set the series in New York. Stone envisioned the Jack Tripper character as a successful, yet underpaid, chef in a fancy French restaurant while the characters who were to become Janet and Chrissy were to be a secretary for a CEO, and a high style fashion model respectively. Silverman felt that the treatment would not play to middle America and thus passed on the script. Silverman then enlisted the services of famed television writer Larry Gelbart, best known for his Emmy-award winning work on CBS's M*A*S*H. Gelbart initially wanted nothing to do with the show, feeling that its relatively simple premise made it substandard in comparison to M*A*S*H. Nonetheless as a favor to Silverman, Gelbart went ahead and developed a pilot episode with his son in law who named the series Three's Company. Gelbart's adaptation closely followed the British series. He envisioned Ritter as "David Bell", an aspiring film maker looking for a place to live who just happened to be a great cook. Ritter's better halves were portrayed by Valerie Curtin who played "Jenny" an employee of the DMV, and Suzanne Zenor as an aspiring actress named "Samantha". Gelbart reset the Ropers' apartment building, which he called the Hacienda Palms, from New York to North Hollywood, California. This plot of this pilot looked much like that of the first episode of the actual show. Liked by Silverman, a pilot was ordered by ABC which taped in early 1976. This format of the show just barely made it on to the fall 1976 ABC lineup but was ousted by what ABC felt were more promising series. Of all the new sitcoms that premiered on ABC for the 1976–1977 television season, only Three's Company and the summer premiere of What's Happening!! went on to a second season. While ABC was in negotiations to re-shoot the pilot, CBS became interested in the show, and made a firm commitment to TTC productions (producers Don Taffner and Ted Bergman's New York based company) to air the show as a mid season replacement in February 1977 with the Gelbart cast. However, at the last minute ABC decided that they wanted the show and made a firm commitment to air the show at midseason with a new cast.