This is the 100th episode.
At the beginning of the episode, Debra is talking about how much she enjoyed Italy because the whole family got along so well. It's a bit of a stretch to say that, especially since Ray was in a horrible mood up until the last couple of days, and Marie was her typical nagging self toward Debra throughout the trip. When Ray is complaining about the new wallpaper stripes being thinner than the rest of the walls, look closely and you'll see that it is actually the exact same.