Jameson's epic reaction to Peter's request to be paid in advance: he cackles.
"You serious? Pay you for what, standing there?"
For some reason, I always bust out laughing when J. Jonah Jameson realizes Mary Jane stood up his son at the altar. The very first thing he says to his wife, with the utmost seriousness in his voice, is "Call the caterer. Tell her not to open the caviar."
Here's one most people miss:
J. Jonah Jameson: I'll give you 150. Peter Parker: 300. J. Jonah Jameson: That's outrageous! Done.
The bit that always slaughters me is the bicycle wheel coming off, bouncing out the window and hitting a car below. Cue yells.
Peter: Um! Sorry!
The spoof of his first attempt to come back to being Spider-Man.
Peter: I'M BACK!
*Jumps, and falls into washing lines and lands on a car. He gets up and his back cracks loudly*
Peter: MY BACK!
As an added bonus, the alarm to the car that Peter fell on goes off as he walks away.
In an interview on public radio, Bruce Campbell discusses his various roles in the films, playing up their importance for laughs. When discussing his usher role in this film, he jokingly brags that he "defeated Spider-Man."