1x18 - The Melancholy of Haruhi Suzumiya

The same exact events in the previous episode once again unfold with slight variations and the gang wearing different clothes. Once again the Brigade, with the exception of Haruhi, finds out that they are trapped in an infinite loop. In this 15,499th loop, Kyon and the others once again are unable to discover how to escape the endless summer. In the same scene in the restaurant, Kyon is unable to stop Haruhi from leaving, hence dooming the world to another summer loop. Kyon again goes to sleep without finishing his homework on the last day of summer.