I will say that for whatever reason when I try to think of Ghostbusters quotes, Bill Murray's lines from this one are the first to pop into my head-- probably because they're not surrounded by good lines like in the first one.
"Guys! You're scaring the straights!"
"Hairless cats.  Weird."
"Hey, I'm a voter! Aren't you supposed to lie to me and kiss my butt?"
"Kitten..."
"You're never gonna get a green card with that attitude, pal."
"Where do you think all this fog is coming from, the SKY!?"

It's a lousier movie like this one that helps point out the strengths of the first one, you can't help but notice how much the big bad in the first flick is tied to the city, it's not just an old pre-historical evil, but it's tied with a recent evil with the building, one of the dark secret histories that you figure New York is drowning in but you don't realize in your day to day life.  That's effective.  Cursed painting?  That could be anywhere... it was moved from museum to museum.  And Peter MacNicol doesn't make a terribly concerning villain (although the second I saw Effie in Hunger Games I thought of MacNicol when he was dressed as the nanny... did anyone else?)

And the second flick also lacks the tight interlaced character stories the first one had, outside of the Ghostbusters being work friends and going into business together and all that, you had Louis and Dana, he was crushing on her and they hook up-- which he always wanted-- but in a way that pretty much dooms the world.  The second one, some characters are just there because they're there (although I did like Louis being their attorney).  That's sort of the sequel curse, you want to being back everyone people liked from the first one but people liked them because they fit into the story so well.

Oh, and while we're talking about Ghostbusters, did anyone read about Bill Murray stopping a bank robber in Tokyo?