Somebody recently tipped me off that Japanese YouTube is a fantastic place to find manzai clips. Manzai is unbelievably fast-paced and slang-ridden, so much so that I'm lucky if I pick up 50% of the dialog. But, you just can't beat the rush when you finally get a joke in a foreign language...
Here are two acts that I understood at least 90% of, and found especially funny:
告白の仕方(アメリカザリガニ)
犬を飼いたい(チュートリアル)
(Japanese only)