平野綾 （ひらのあや [Hirano Aya {Aya Hirano}])

So the voice actress for the main character of 涼宮ハルヒの憂鬱　（すずみやはるひのゆううつ　[suzumiya haruhi no yuuutsu {The Melancholy of Haruhi Suzumiya}]) is Aya Hirano (above). And yeebus, I had no idea her actual voice was so high:

Hey Hey Hey
http://www.youtube.com/watch?v=1taPDCzOJLE&mode=related&search=

In the beginning of the clip while it's doing an intro for her you can hear the voices she does for the character in the anime and the songs that she sings (she sings the intro/end for the anime and other songs from the show). Then around 1.30... when she starts talking on the show... ... <_<>_> o.0 it's like a squirrel on helium!

A little before 2.30 she speaks in a different voice for the hosts. The rest of the clip i think she's making up nicknames for hosts?

one of the songs she sings for the anime:
God Bless
http://www.youtube.com/watch?v=xiEDIrFj3Cs