Best Sci-Fi TV Series Ever Made: The Definitive Argument Thread

[FrostBear]

Science fiction television has produced some of the greatest storytelling in the medium's history. The debate about which series sits at the top is genuinely interesting because different shows excel at completely different things. The Wire is often called the greatest television series ever made in any genre. Science fiction has its equivalent debates and they're just as passionate.

Babylon 5 was the first series to tell a single planned story across five seasons. The arc was mapped before filming began. That discipline produced something genuinely different. Deep Space Nine ran simultaneously and both shows explored politics war and moral compromise in ways Star Trek hadn't before. Battlestar Galactica's 2004 reboot was prestige television before prestige television was a phrase. The first two seasons were extraordinary. Stargate SG-1 ran ten seasons and maintained remarkable consistency. The Expanse is the most scientifically rigorous science fiction series ever made. Black Mirror proved anthology science fiction could work at the highest level.

Some shows are beloved for specific eras and disappointing in others. Some started weak and became exceptional. Some peaked early. What's your actual pick and why?