Doctor Who (2005-2023); Highs and Lows, Ups and Down, Timeys and Wimeys

Doctor Who has long enjoyed a certain prestige as the longest-running science fiction television series. In 2010, Guinness World Records recognised it as 'the most successful science fiction television show in the world,' based on metrics such as DVD sales and online viewership.

The show has been running for so long that even its revival, relaunched in 2005 after being shelved in 1989 for declining quality, is now 20 years old. Heck, it survives into the modern day through a third revival tailored specifically for streaming, backed these days by big daddy Disney money (not to mention the works of Big Finish, which have secretly been keeping the lights on for decades and will presumably continue on long after humanity is extinct and the world has been consumed by flames - eta: next Tuesday).