I really, really like this track by Omodaka, called ‘Korikori Bushi’:
Well-produced arpeggio-filled chip tunes plus what is apparently the oldest Japanese song in existence, all with a cute video.
If you liked that you may also enjoy ‘Yosawya San’, with the cute head-bobbing geishas:
Both tracks are available in the iTunes Music Store.
(If you want to know more about those chipmunk-y electronic voices, I recommend this article from The New Yorker.)