Near the beginning of Ghostbusters, right after our heroes are given the boot by Columbia University and forced to make a real run at their fledgling ghostbusting business, parapsychologist Dr. Peter Venkman (Bill Murray) has a sort of telekinetic premonition of his own.

“Will you guys relax?” he says to his worried colleagues, Egon Spengler (Harold Ramis) and Raymond Stantz (Dan Aykroyd), in Murray’s signature deadpan. “We are on the threshold of establishing the indispensable defense science of the next decade: Professional Paranormal Investigations and Eliminations. The franchise rights alone will make us wealthy beyond your wildest dreams.”

On June 7, 1984, Ghostbusters hit theaters and quickly became one of the highest grossing films of its decade, eventually pulling in close to $300 million at the box office. But who aside from Venkman could have predicted that 30 years later the story of some schlubby scientists running around the Upper West Side of Manhattan in exterminator uniforms, capturing ghosts and battling Sumerian gods of destruction, would turn into the indisputable cultural phenomenon that it is today? Because in 2014 Ghostbusters remains not just a movie, but a world in and of itself, one that has spawned a jaw-dropping number of action figures, comic books, television shows, Halloween costumes, novels, fan fiction sites, and video games (not to mention the Bobby Brown song “On Our Own,” which peaked at No. 2 on the Billboard Hot 100, and one of the better sequels of all time in 1989’s Ghostbusters II). It’s a franchise that rivals the Star Wars universe in terms of marketability and staying power, an extraordinarily rare feat for any film, let alone a picture where marshmallows figure so prominently.

For those readers who grew up in the '90s, years after both the original film and its sequel had vacated movie theaters, Ghostbusters still felt fresh. Every week through 1991 the newest adventures of Venkman, Spengler, and Stantz were beamed out to the children of America via ABC’s The Real Ghostbusters. All 147 episodes (including a 13-episode Slimer spinoff) were then later available via syndication on the USA Network and FOX until 2001, firmly placing the Ghostbusters in the hearts and minds of a new generation of young geeks, many of whom weren’t even born when the first film premiered.

In addition to the cartoon, over a dozen Ghostbusters videos games have been produced over the years for systems ranging from Atari to NES to Sega Genesis to Xbox to Playstation and, most recently, your iPhone. Up until the late-'90s you could drink green Ghostbusters-themed Hi-C Ecto Cooler, for those fans who were curious about what it was like to guzzle psycho-reactive slime. There were Ghostbusters candies. Ghostbusters “Slimer” bubble gum. Heinz tomato sauce complete with Ghostbusters-shaped pasta. Ghostbusters pillowcases and sheets. You could literally eat, drink, and sleep Ghostbusters up until the start of the new millennium if you wanted to.

But what about the Ghostbusters franchise makes it so utterly merchandisable, even today? (LEGO will release a 30th anniversary Ectomobile set this month and LRG just dropped this very excellent “Stay Trappin” T.) It starts, of course, with a really good movie, one that caters to the two things Hollywood has depended on for decades: hilarity and action.

What enabled Ghostbusters to be such a monster success in 1984 is that it’s not a parody of a science-fiction movie, like Mel Brooks’ Spaceballs or Woody Allen’s Sleeper; it's a science-fiction movie. Aykroyd and Ramis, who co-wrote the film, didn’t set out to ridicule pimple-faced geeks; they were the pimple-faced geeks (especially Aykroyd, who envisioned the Ghostbusters traveling through space and time in early drafts of the script). They just happened to also be two of the greatest comedic minds of their generation. The film embraces the genre clichés of laser beams, pyrotechnics, and esoteric psychobabble, something critics found fault with on first viewings.

“Ivan Reitman, the director, subsequently has to contend with spectacles like a rooftop demonic shrine and a 100-foot marshmallow dressed in a sailor suit, marching up Central Park West,” wrote Janet Maslin of the New York Times, before going on to call the movie a “messy, near-miss” film. “Not surprisingly, with all this going on, there is more attention to special effects than to humor.”

But these are the details that 30 years later make Ghostbusters such a perfect amalgamation of supernatural action flick and side-splitting comedy. The film works because it was a special effects spectacle as much as it was an extended Saturday Night Live sketch. Viewers could laugh at Bill Murray groaning, “He slimed me,” during one scene, and then want to strap on a proton pack and zap some poltergeists with the rest of the guys in the next. The thought of New York City getting trampled by a giant, demonically-possessed Stay Puft Marshmallow Man was hilarious, but also kind of visually awesome at the same time.

Since the release of the movie, the phrase “He slimed me” has become something of a de facto slogan for the franchise. The gluttonous green ghost that causes Murray to utter those famous words became known as “Slimer” and was subsequently plastered on practically every piece of Ghostbusters merchandise in existence. The line was nominated for the American Film Institute’s “100 Years…100 Movie Quotes” list.

But what’s important to note here is that there is nothing inherently funny or particularly witty about the line. In fact, it’s kind of lame, better suited to a '90s Nickelodeon game show than a Hollywood blockbuster. What made that phrase—and so many of the other lines from Ghostbusters—so hilariously quotable was the sheer comedic brilliance of Murray, Ramis and Aykroyd.

Though the chemistry between the leads is apparent from the opening credits, after watching the movie for about the billionth time it becomes clear that the true genius of Ghostbusters is not necessarily a former National Lampoon writer or an SNL alumnus, but Rick Moranis as Louis Tully, the bespectacled accountant-turned-“Keymaster” who becomes possessed by the demon Vinz Clortho. The entire cast is phenomenal—Sigourney Weaver as Venkman’s love interest Dana Barrett, Annie Potts as the gang’s nasally secretary Janine Melnitz, Ernie Hudson as Ghostbuster Winston Zeddemore, David Margulies as “Mayor Lenny”—but Moranis provides the most consistently laugh-out-loud funny performance between the two films. The sequence where the possessed Louis describes the three “pre-chosen forms” of Gozer the Traveler to Egon while wearing what looks like colander on his head should go down in movie history as one of the most hilarious scenes of all time.

Ghostbusters is the rare film in which every performance is spot-on, every joke lands, and every scene perpetuates the illusion of a universe outside of the humdrum world that we know. In 2014, it oozes nostalgia, but at the same time can be enjoyed without irony. Everything from the red and white Cadillac “Ecto-1” to the proton packs to the beige flight suits to the funkadelic theme song perfectly catered to the toy and collectible-obsessed children of the late 20th century and turned a summer blockbuster into a multi-million dollar phenomenon.

Three decades later Ghostbusters is one of the most enjoyable films of all time and perhaps the only movie where comedy and science fiction were truly allowed to co-exist on the screen without any awkward animosity. Once again the proverbial crossing of streams seems to have saved the day.

Jackson Connor is a writer based in Brooklyn. He tweets at @JacksonMConnor.

RELATED: The Best Movies of the '80s
RELATED: The 50 Funniest Movies of All Time