The Real Ghostbusters may have been another toy-driven 80s cartoon, but it was a good toy-driven 80s cartoon.
I say this without any irony: The Real Ghostbusters is quite possibly the second best movie-to-TV spin-off after M*A*S*H. (I don't count Buffy the Vampire Slayer because Whedon was openly looking to override the existence of the original film, rather than jump-off from its continuity like other spin-offs did.)
It had all the same problems that other 80s cartoons created mainly to move a line of toys did, certainly. But it also had substantial up-sides like a nifty pop-art visual sensibility featuring warped grotesques representing all manner of the supernatural recalling the iconic art-style of Ed "Big Daddy" Roth, with abstract/surrealist dreamscapes split somewhere between Bosch and Dali used to depict alternate-dimensions and a night-time color scheme that spread Times Square neon across the whole of the city.
But really, it's fondly remembered today because some put actual intellectual effort into a good number of the series' screenplays. Episodic toy-toons of the era were often written by a who's-who of established and up-and-coming genre writers, and the central premise of Ghostbusters -- that it's not just "ghosts" that are real and making trouble, but the entire pantheon of mythic/ancient demons, gods, etc -- was basically an unattended candy-shop for its staff of reliably-geeky writers. These are five of the best -- just in time for Halloween...
WHEN HALLOWEEN WAS FOREVER
Even as kid, I could always tell (from the exposition dump) when TRGB was using important creatures/concepts of mythology (or movie references, like that time they met the ghost of Citizen Kane) as a heavy rather than something they'd made up -- and I usually made a note to find out more about it later (there was no Google then, kiddies -- so you really did have to remember to look stuff up the next time you found yourself at either a library or the home of someone who actually owned an encyclopedia).
The heavy in this one is no less than the (para)physical incarnation of Samhain (pronounced "Sahm Hane" here), depicted as a cloaked figure with a Jack O' Lantern head who rallies all the ghosts of New York to his aid -- including Ghostbusters sidekick Slimer, who has to choose sides. It's one of the more visually "big" episodes of the first season, with tons of ghosts on-screen at a time, and Samhain would go on to be a recurring villain in the franchise.