Can't get enough green tea? How about a Kit Kat Green Tea? They're only available in Japan and they are a limited edition so you may be out of luck, but it doesn't hurt to try. While you're at it you can also try to get your hands on the Kit Kat Azuki Bean, Green Tea, and Cream, also available in Japan.
Here's an article about the popularity of Kit Kat bars in Japan and a Wikipedia entry about Kit Kats, including a list of some odd flavors that have appeared over the years.