Previously, C is for Community, and now here comes D. Which you will already know the answer to because of the title 🙂
D is for Doctor Who.
This show has been on for decades, literally. The newer series was a reboot which began in 2005, and was one of the earliest shows I every became a fan of. It was my introduction into being sucked into a television show, and wanting to explore all the behind the scenes and secrets of a show. For that, Doctor Who will always have a soft spot in my heart.