It's odd to think that, once upon a time, a TV show set in space — one that declared, in its opening narration, as the cosmos being the "final frontier" — was considered the pop-cultural equivalent of an unwanted party-crasher. Yes, a concept like Star Trek was both of its time and clearly ahead of it; history has more than vindicated Gene Rodenberry's notion of boldly going where no man had gone before. But given the number of top-notch shows set in the far reaches of the galaxy and that used genre for pulpy and profound purposes over the last 30 or so years, it seems crazy to think that one of the most groundbreaking SF series was a network pariah and a ratings dud. Today, there's an entire cable network devoted to this kind of programming. You can't turn on your TV/Roku/cut-cord viewing device without bumping into spaceships, alien invasion and wonky sci-fi food-for-thought.
Science fiction has been around in one form or another since the early-ish days of television, both here and abroad, and its legacy now looms larger than ever. So what better time to count down the 40 best sci-fi TV shows of all time? From anime classics to outer-space soap operas, spooky British anthology shows to worst-case-scenario postapocalyptic dramas, primetime pop hits to obscure but beloved cult classics, here are our choices for the best the television genre has to offer — submitted, for your approval.