Ghostbusters is getting to be like Marvel in its number of disconnected spinoffs and expanded universes...
It started almost right away with The Real Ghostbusters (so called due to an oversight when licensing the name from the 70s TV show meant the licence holders could rush out a new cartoon version) with blonde Egon and redhead Ray for ease of telling them apart (and less-Murray-ish Venkman and clean-shaven Winston and Cindi Lauper Janine for kid-friendly youthfulness). It got the toys and most of the spinoffs like comics initially, including the first comics for the entire run published by Marvel UK. This ran with the basic case-of-the-week premise, which then got stepped on by Ghostbusters II.
Extreme Ghostbusters was a next generation for Real, and one of its members (Kylie) was brought into the IDW Comics version of the main universe, which after some initial miniseries got a consistent style - which is cartoony, but not the same way the cartoons are - and they also did Real Ghostbusters comics, and they’ve done a crossover story.
The recent big Kickstarted board/miniatures game uses the IDW style. (If you want non-cartoony miniatures of the main characters you have to go unofficial with companies like Crooked Dice making them...)
Ghostbusters: The Video Game is far from the first Ghostbusters computer game (I fondly remember spending about twenty minutes beating the ZX Spectrum version after getting the invisible supercar cheat) but gets that definitive title by having the team do voice work, CG likenesses, and a chunk of the script. It’s essentially the unmade Ghostbusters III happening in front of a FPS. It sets up a universe where the Ghostbusters are still working fairly consistently, which the IDW comics fit into (even giving a guest shot for the player rookie).
There was also a novel set a couple years after GB2, intended to start a series, with Venkman running for mayor.
The franchise idea jumped on by the RPG has never gotten a major outing, though it’s common among fan films and the like. (DIY Ghostbusters are also popular with cosplayers who don’t happen to look like the actors, which can be a great source of pictures for RPG characters. I suspect this guy is an intern.) It would seem like a good setup for a TV series, considering what you can do with special effects these days...