Want Funny Background Event taken to its hilarious zenith? Rewatch the prison scene again. As Egon is explaining Gozer and Zuul's plans, the prisoners that keep passing by become increasingly enthralled by the topic at hand!
Egon: He decided that society had become too sick to survive. [Pauses to glance at the other prisoners, then continues his info-dump.]
The way Egon puts an end to Janine's flirting questions.
Egon: I collect spores, molds and fungus.
Venkman teasing Egon shortly before going to confront the library ghost:
The scene at the Mayor's office, when Ray explains how Obstructive Bureaucrat Walter Peck caused the ghosts to be released:
Ray: Everything was fine with our system until the power grid was shut off by Dickless here. Peck: They caused an explosion! Mayor: Is this true? Venkman: Yes, it's true. This man has no dick.
Even the censored version is amusing enough to warrant note.
Ray: Everything was going fine until the power grid was shut off by this weasel here. Peck: They caused an explosion! Mayor: Is this true? Venkman: Yes, it's true. This man is some sort of rodent. I'm not sure which.
Except, of course, weasels are Mustelids, not Rodents. So, once again, Venkman doesn't know what he's talking about. Which only makes it funnier.
Another censored version has a slightly altered yet no less funny exchange, with Ray calling Peck "Wally Wick" instead of a weasel.
An issue of Nintendo Power with an article on the 2009 games had the guts to put up a picture of Peck with the caption: "Yes, it's true. This man has no Wii".
An airing on British terrestrial TV censored this scene by overdubbing the offending words with dialogue from elsewhere in the movie - so Venkman's punchline becomes "Yes, it's true. This man has no twinkie."
It's made even funnier by the resulting commotion / averted fistfight, during which Venkman can be heard audibly protesting "Well, that's what I heard!"
Venkman's reaction when his argument wins the day and Peck, swearing revenge, is ejected from the building is classic:
Venkman: Bye. Peck:[Being pulled out] I'll fix you Venkman, I'm gonna fix you... Venkman: I'm gonna get you a nice fruit basket. I'm gonna miss him.
On the commentary, Ivan Reitman relates meeting with William Atherton after the film became a hit, and he was quite upset that suddenly random people were calling him "dickless," including one incident where a whole bus full of tourists stopped to yell it at him.
When Ray, Egon, and Venkman are touring the old firehouse:
Spengler: I think this building should be condemned. There's serious metal fatigue in all the load-bearing members, the wiring is substandard, it's completely inadequate for our power needs, and the neighborhood is like a demilitarized zone. Stantz: Hey, does this pole still work?? (slides down the pole) Wow. This place is great! When can we move in? You guys gotta try this pole! [...] Venkman: (beat) I think we'll take it.
Bill Murray's face when the Cardinal of New York walks in is quite possibly the greatest deadpan reaction gag of his career, and when you consider the range of said gags, that's saying something.
The moment in the original when Ray decides that Bureaucratese is the best way to deal with an invading God from Dimension X:
Ray: Gozer the Gozerian? Good evening. As a duly designated representative of the city, county and state of New York, I hereby order you to cease any and all supernatural activity and return forthwith to your place of origin or to the nearest convenient parallel dimension.
Venkman: ... that oughta do it, thanks very much Ray.
This is anIronic Echo of Ray saying "GET HER!" to the ghost in the New York Public Library in the beginning of the movie, which Venkman was amused by.
After catching Slimer:
Ray: Sir, what you have there is what we refer to as a focused, non-terminal repeating phantasm, or a Class Five full roaming vapor. Real nasty one, too!
Peter: Now, let's talk seriously. For the entrapment, we're gonna have to ask you for four big ones. Four thousand dollars for that. But we are having a special this week on proton charging and storage of the beast, and that's only going to come to one thousand dollars, fortunately.
Hotel Manager: Five thousand dollars? I had no idea it would be so much. I won't pay it.
Peter: Well, that's all right. We can just put it right back in there.
Ray: We certainly can, Dr. Venkman.
Hotel Manager: No, no, no, no! All right!
In the widescreen version, you can see Egon feeding Peter the numbers via hand signals.
The conclusion of the Running Gag of Louis locking himself out of his apartment, with Rick Moranis' gloriously pathetic delivery of "Somebody let me iiIIIINNN!"
Later, we get to see the party, culminating with Vinz Clortho in the back room getting a coat tossed in his face.
The Central Park carriage-driver's reaction to the possessed Louis Tully talking to his horse, growling at him with inhuman red eyes, and running off screaming about how the apocalypse is at hand:
Carriage-driver: What an asshole.
The conversation Vince had with the horse was funnier.
Be glad the horse didn't turn out to be the Gatekeeper. Very glad.
When Gozer is revealed as having taken on the form of the Stay-Puft Marshmallow Man. The look on his face is priceless, too - he looks so happy!◊
The Smash Cut moment when, having arrived at the Dana's building to battle Gozer and been greeted like conquering Big Damn Heroes by the people, we cut to see the Ghostbusters exhaustedly pulling themselves up the stairs to reach Dana's floor.
Peter: Where are we? Ray: Looks like the mid-teens. Peter: Well, when we get to twenty let me know. I'm gonna throw up.
After Gozer is destroyed and the damage is done, the Ghostbusters all emerge from the rubble. Everyone's covered head to toe in marshmallow foam except for Venkman who's relatively clean. There's a moment where the guys are looking at Venkman like, "Wait, what the hell?"
On a related note, it looks as if Dana was killed in the explosion. Ray, who had been making jokes about the smell of burned dog hair, realizes his mistake and apologizes with extreme sincerity and sympathy. Peter turns around to look at him... to see him standing there quite seriously, covered in marshmallow.
The completely serious way Venkman responds to the "Twinkie" metaphor.
Winston: Tell him about the Twinkie.
Venkman: *dead serious* ...What about the Twinkie?
When the boys are shooting at Gozer and Ray exclaims: "Aim for the flattop!"
Winston applying to work for the Ghostbusters.
Janine (completely deadpan): Do you believe in UFOs, astral projections, mental telepathy, ESP, clairvoyance, spirit photography, telekinetic movement, full trance mediums, the Loch Ness monster and the theory of Atlantis?
Winston: Ah... if there's a steady paycheck in it, I'll believe anything you say.
When the police arrive at Ghostbuster HQ, Janine greets them with this priceless line;
Janine: Dropping off or picking up?
Also her line during another endless day in the office:
Janine: I've quit better jobs than this. (Answers the phone.) Ghostbusters, whaddaya want?!
The entirety of their first case snagging Slimer is one long CMoF the second they reach the elevators.
Elderly Gent: What are you, a cosmonaut? Venkman: Ah, no, we're exterminators. Someone saw a cockroach on Twelve. Elderly Gent: Must be some cockroach. Venkman: (deadpan) Bite your head off, man... (the elevator opens) Venkman: Going up? Elderly Gent: I'll take the next one.
The calm bickering on the elevator over how their gear is untested leads to:
Ray: Okay, switch me on. (Egon hits the power switch, and slowly nudges Venkman over to one side in the cramped elevator)
Peter going to Dana's apartment to find she's been possessed by the a demon, Zuul, "the gate keeper".
Zuul:(opens the door) Are you the key-master?
Peter: Not that I know of.
(Zuul rolls her eyes and slams the door. Peter knocks again.)
The scene where Egon rolls his eyes and awkwardly hugs Janine apparently went a little differently in the original script:
Janine:(worried) Egon, there's something very strange about that man. (she indicates Louis)I'm very psychic usually and right now I have this terrible feeling that something awful is going to happen to you. I'm afraid you're going to die.
Egon: Die in what sense?
Janine: In the physical sense.
Egon: I don't care. I see us as tiny parts of a vast organism, like two bacteria living on a rotting speck of dust floating in an infinite void.
"Right. That's bad. Okay, all right. Important safety tip, thanks Egon.
While the sequel is considered slightly inferior to the original, it does have this:
Venkman: Say, Johnny, where the hell are you from? Janosz: Uh, de Upper Vest Side...
Also from the sequel, when the Ghostbusters were committed:
Ray: As I explained before, we think the spirit of a 17th century Moldavian tyrant is alive and well in a painting at the Manhattan Museum of Art.
Psychiatrist: Uh-huh, and are there any other paintings in the museum with bad spirits in them?
Egon: You're wasting valuable time. He's drawing strength from a psychomagnotheric slime flow that's been collecting under the city.
Psychiatrist: Yes, tell me about the slime.
Winston: It's very potent stuff. We made a toaster dance with it. And a bathtub tried to eat his friend's baby.
Psychiatrist: A bathtub?
Venkman: Don't look at me. I think these people are completely nuts.
Again from the sequel, the entire scene where Egon and Ray show Peter and Winston the effects of the mood slime, especially the dancing toaster.
Ray: We sing to it, talk to it, say... supportive, nurturing things to it. Venkman: You're not sleeping with it, are you Ray? (Ray shakes his head; Egon hangs his head in embarrassment.) Winston: It's always the quiet ones. Venkman: You hound.
Louis' very helpful defense during the court room scene.
Louis: Your Honor, ladies and gentleman of the ... of the audience, I don't think it's fair to call my clients frauds. Sure, the blackout was a big problem for everybody. I was trapped in an elevator for two hours and I had to make the whole time. But I don't blame them. Because one time, I turned into a dog and they helped me. Thank you.
The judge's reaction is priceless.
As is Egon's:
Egon: Very good, Louis. Short, but pointless.
We can't forget Louis' intro:
Louis: This isn't my kind of thing. I mostly do taxes, some probate stuff. I got my law degree at night school.
Ray: That's OK Louis. We were arrested at night. [Face Desk]
Our peek into Egon's childhood: "We had part of a Slinky, but I straightened it."
Janosz's line after being hosed. "Vy am I drippings vith goo?"
At the end of Pete, Ray, and Egon's fight with the Scoleri Brothers. When they activate the trap while heroic music is playing in the background, the way the music ended with the skinny brother getting sucked in with his glowing eyes bulging out wide before the trap's lid quickly shuts closed made it look like a funny cartoon sequence ending with funny cartoon music.
Janine's one-sided phone conversations when business starts picking up: "I'm sorry, but they can't get to you until after the new year... Well then just don't go in there!"
"Ray... we'd like to shoot the monster. Could you move, please?"
And the fact that their immediate reaction to Ray being possessed is to immediately hose him down.
Vigo doing his Badass Boast on New Year's Eve - and Janosz being bored out of his skull.
Janosz tries to convince Dana that Vigo's possessing Oscar is a good thing.
Janosz: There are many perks to being the mother of a living god...
Ray attempts to be diplomatic to the Mayor of New York.
Ray: And I'd like to say that almost fifty percent of us voted for you in the last election.
Egon's insults to the slime sample during their demonstration to Peter and Ray.
You're nothing but an unstable short-chain molecule!
You have a WEAK electro-chemical bond!
How Egon describes how Peter's been since the first movie.
He was borderline for a while, then he crossed the border.
A man asked Egon and Ray if they can make a Proton Pack for his son.