If you can, go and google the Ghostbusters script. You'll find the original pre-shooting script and it's amazing how less funny than the final product. Not so surprising, a lot of the improvements were in Bill Murray's lines. He totally carried the whole movie.
They hold up quite well don't they? actually this movie still holds up for the most part in general. Part 2...eh its so so, but holds up decently. I really hope GB3 doesn't happen, ghost Venkman and a most likely a poorly put together group of "new" Ghostbusters.
I don't mind the idea of a new team, but you know their going to go with people like Jack Black or Ben Stiller, Owen Wilson...shit like that.