I agree with Atheist Revolution. I think the "endless eight" story arc could have (and should have) been resolved in just three episdoes.
Episode one (of the "endless eight" plot) would be exactly the same as it is, with the SOS Brigade going through the last two weeks of summer, with no indication of anything wrong or strange going on.
Episode two would also be unchanged, with the characters doing the same things, and Kyon getting strange feelings of deja vu, then getting called in the night by Mikuru and being told by the other members that they've been re-living the last two weeks of summer more than fifteen thousand times. They spend the rest of summer doing their activities not knowing what to do to break the endless loop, then summer ends with Haruhi saying they have one day of summer left but that they've done all the activities and everyone can have a free day, and then leaving the restaraunt, and Kyon wanting to stop her but not knowing how.
Episode three should have been the episode that ends with Kyon stopping Haruhi from leaving and telling everyone they should all come to his house and do homework together, and by doing so break out of the loop.
Instead, we get episode after episode after episode after episode where the group spend the two weeks doing more or less the same things again and again and again, and in all but the first Koizumi, Mikuru and Yuki give Kyon THE SAME DAMN STORY about how they're re-living the last two weeks of summer over and over again. After about three or four episodes of this you'll want to beat your head against a wall.
I really can't help wondering if the Japanese producers told the writers they had to come up with scripts for fourteen episdoes and the writers were really low on ideas so they came up with a cop-out way of taking one episode and just repeating it eight times. That's really the only explanation I can think of.
My theory is that after they finished preparing a second season containing "Bamboo Leaf Rhapsody," "Endless Eight," "The Sigh of Haruhi," and "The Disappearance of Haruhi," some executive decided to make money with the "Disappearance" episodes by combining them into a theatrical movie, leaving the writers and animators to try and fill seven empty TV slots with padding.
Teach your friends the truth!