What: Star Wars, Episode V: The Empire Strikes Back, the 1980 sequel to George Lucas’s epic. The continuing story of our band of heroes tempted fans with this trailer:

Why: Showing a humility and foresight few would have imagined, George Lucas sought out his old USC film school professor, Irvin Kershner, to direct Empire. Kershner had previously directed such films as the potboiler Eyes of Laura Mars and the espionage spoof S*P*Y*S, none of which would let anyone confuse him with Hitchcock or Fellini. Kershner said no, but his agent insisted. And so, perhaps only to help his protégé, Kershner directed the greatest science-fiction epic ever. The actors, somewhat raw in Star Wars, had now come into their own, showing a range that made even the Han-Leia-Luke (um, ick) love triangle deeply involving. The script by Leigh Brackett and Lawrence Kasdan was the crispest of the series. Lucas’s revelation that Darth Vader was Luke’s father blew audiences’ minds; if you saw it in the theater on day one like I did, you most assuredly did not see that coming. And oh my, was it pretty. Cloud City, Dagobah, and the ice planet Hoth looked real, and the Rebel battle against the AT-ATs remains unequalled in sci-fi spectacle.

Impact: As the 12th highest grossing film of all time, Empire still can’t compete with Star Wars, which is only behind Gone with the Wind on the all-time list. But while Star Wars is the epitome, Empire is the franchise. Star Wars was a closed loop, but Empire doesn’t even have an ending. As Luke, Leia, and the droids stare out the window and the Rebel fleet limps off to parts unknown, Lucasfilm challenges you: “You want to know more, right? You really, really do?” We did, and Lucas had the biggest science-fiction franchise in history.

Personal Connection: I’ve done lots of projects for and around Lucasfilm, working on three Star Wars games and creating a couple dozen puzzles for Star Wars Gamer and Star Wars Insider. My team also ran the Tatooine Parlor at Star Wars Celebration, allowing players to shoot womp rats, play the game Sabacc, and decide who shot first, Han or Greedo. I’ve enjoyed my relationship with Lucasfilm, as they let me—and hundreds of other creatives—make up cool things for their expansive galaxy. My latest foray commemorated Kershner’s passing last week, over on the Wired site, with artist Corey Macourek and I contributing a Star Wars Hanukkah Special. (My biggest contribution to Lucas’s empire has nothing to do with Star Wars, though. More on that in another entry.)

Other Contenders: Star Trek II: The Wrath of Khan, the brilliant sequel to the original series episode “Space Seed”; “Best of Both Worlds”, Star Trek: The Next Generation‘s indomitable centerpiece; “Toys in the Attic”, the most invasive episode of Cowboy Bebop; “Our Mrs. Reynolds”, the first impact of Christina Hendricks’s Saffron on Firefly; Aliens, which told all other sci-fi horror flicks, “Game over, man!”; “The Girl in the Fireplace”, where, on an abandoned spacecraft, Doctor Who falls in love with Madame de Pompadour.