Out of all of the events in the Haruhi novels, "Bamboo Leaf Rhapsody" is the one I remember most clearly. This is partially due to the relative simplicity of the plot; compared to some of the contortions in later arcs, nothing much happens, but it's all rather straightforward. What I like about this particular story is how casually epic it is. Time travel stories tend to involve dramatic means of making the leap, whether it be via a machine or portal or device. Here, Kyon travels through time in the most mundane way possible. Yet at the same time he's given glimpses of the mind-boggling power that his associates wield. Finally, if I may lapse into sentimentality, there's the sense of destiny. Kyon's actions while time-traveling are integral to the present, a plot device that carries echoes of one of the most satisfying story arcs in Kimagure Orange Road. (And for that reason I think Kyon's real name is Kyousuke.)
I'm actually kind of glad it's taken this long to S2 to start: it's given me enough time to forget the details of the novels. Now I can enjoy the anime instead of getting bogged down in the details.