Here’s the Sci Fi Channel’s reason why Stargate SG-1 (running for 10 years and 200 episodes) is the world’s longest running science-fiction show, not Doctor Who (running for 40 years on and off and approximately a billion episodes):
Guinness awarded the title of longest-running sci-fi series in tv history to Stargate, which took the title away from X-Files (at the 203rd episode, technically). Both shows overshadow Doctor Who in that they had consecutive episodes. Doctor Who while it ran several hundred episodes, had long gaps of not being in production, far longer than a regular hiatus. The show was revived several times and I’m told one of the gaps between production was over ten years.
All they had to do was say “longest running US sci-fi series” and they’d have been off the hook, but no, they just had to start making stuff up…