In Haruhi second season, there was 8 episodes that have been the same. The series of "Endless Eight" episodes are literally doing the same things over and over again. But it's not really the same thing, they re-animating and re-dubbing whole episode, they didn't being lazy and use the same source.
Here's the same sequence of different episodes when Haruhi called Kyon to ask him to swim with others at the pool:
As you can see they give different tones, angles, outfits, etc. That's too much effort for same situation all over the episode for eight episodes straight. So why did they doing it? Did they also did it in light novel? What is the point of "Endless Eight"?