This isn't a saying that's talked about like others from the show but I think it's pretty funny at times, such as in the Capt Horatio Hornblower episode from 9/23/51. When Don falls off the ship and someone yells "MAN OVERBOARD!!" Jack responds with "Good. Good." Of course they had argued earlier in the show with Don claiming he was fat due to overeating for the show's jokes.
Peter