In the wise words of Kyon, “A ponytail increases a girl’s charm by 36%.” So here’s Suzumiya Haruhi.
As a probably unexpected comment, one thing on Haruhi – the ponytail/headband thing combo looks a bit goofy most of the time. She looks better with the headband thing gone and just the ponytail. Basically one or the other, but not both. That’s how she had it in Disappearance with her long hair, and that was a killer combo. The same applies to other headband-wearing characters such as Akemi Homura, although she never actually has a ponytail in the show/movies.