There's a great scene (can't remember which episode) where Fran and Niles are both on their way to ask Maxwell for vacation time off. They can't both do it so they argue and Fran ends up telling Niles he can have it.

She starts walking up the stairs and Niles RUNS to Maxwell's office at full speed and when he gets there Fran is sitting on his desk smiling cuz she already beat him to it.

It cracks me up every time.