In the more than 50 years since Star Trek made its debut on NBC, the franchise has seen more than a dozen feature films and has its sixth spinoff series on the way later this month with CBS All Access’ Star Trek: Discovery. For all the many amazing stories told in the decades to come, it’s hard to beat the original Star Trek. Running for just three seasons, the series has become synonymous with the science fiction genre and emerged a cultural touchstone that has entertained, educated and inspired dreamers all over the world.
Like any series, Star Trek has its ups and downs. The best episodes, though, rank among television’s very finest. We’ve assembled a list of Star Trek’s 20 best original series episodes, each of which has withstood the test of time in delivering stories that, despite their spectacle and imagination, are ultimately about exploring the human condition. As such, many of the themes explored on Gene Roddenberry’s show have only become more relevant and the show’s 23rd century setting all the more important a future to which we might aspire.