Besides what you can think of the movies, and especially its sequel, it is a fact that there's so number of similarities between those two productions, and of course I'm not referring here only to the logos... there's actually common aspect in both plot and directing. I'll try to document on this page as much as similarities I found being the most detailed possible.
One of the first similarities is the plot itself.Yes, there's no Slime nor Vigo in GB1 , but if you see the the story globally you will notice that in both movies the GBs pass from a unsatifactable Job position to a way better one. In GB1 , the guys, loose their job at Columbia University and build up "Ghostbusters" for living , swichting from a poor situation to fame & success. Although in GB2 all the GBs have a steady work they are unsadisfited with it: Peter is in a B series talk show, Ray runs an Occult book store but he secretly dream of the Ghostbusters returns , Egon is recycled in private research , and, although no particular notes of negativism is seen, it certainly would like to continues his "first-love" studies : the paranormal. An unexpected rise on PKEs ( the big twinkie in GB1 as the Gozer's come and Vigo arrival in NYC on GB2) will turn out very lucky for the GBs
At this point , in the movies, the GBs have successfully busted they first spook(s), Slimer at the Sedgewich Hotel in GB1 and the Scoleris Bros in GB2 in the Court. Just after they got them , in both movies, the GBs comes out of the room triumphally with people all around them and Peer declare a "sensation quote" : "We can , we saw, we kicked its ass" and "We're the best, we're the beautiful ,we are the only Ghostbusters"
The first bust conclusion is the beginning of the climax which lead us to a montage presenting the GB in full activity. The "Ghost fever grips New York" in GB1 , with the magazine appearing on the screen or the montage presenting the GB busting all over the city with "Ghostbusters Rap" by Run-DMC on the background.
Well, this images don't need any comment .. they are both taken from the montages, the scene is identical, except for Winston , naturally, that is now part of the GB crew. This probably has been made expressly as a recall to the first movie.
Here again, although those two scenes are not parallel, the first happening at the end of the montage, the second in the middle, the shot are nearly identical.. Being to severe? In my opinion they could have shown the new GB2 logo differently.
Although those scenes have nothing in common by theyself , the Libby's ride is a recall to the Stay Puft Grand Entrance. Like if the authors needed something big-in-the-eyes again, since the Stay-Puft entrance in GB is the most famous scene of the movie. Later Dan Aykroyd himself judged the Libby ride an error.
The guys discovered the plans of the evil presence: take over the world. Therefore they have to report it to the authorities. In both movies, they meet with Lenny. In both cases they are not believed in the beginning. In each of the scenes there's an antagonist defending the opposite theory of the µGhostbusters, Walter Peck in GB1 and Haldemaier in GB2.
What I call the "One out of three" scene also repeat in the movies. Basically you have a situation where there's a choice to make about who of the 3 Ghostbusters may achieve something. The answer is not given by words but rather by looking at the chosen. This happen in GB1 when Peter is chosen to speak with the Library ghost and in GB2 when "some has to go down here" in the hole in First Avenue
At the beginning of two montages , Dana's watching at the GBs successes on TV. The scene is identical, except that in GB2 she's carrying Oscar.
Ok, maybe this is a little of a harard , still, in those two scen , a pin pointed map is shown with someone explaining some wieard supernatural phenomenon to a third person.
Have more similarities that I missed? I'll add them here!