Surely you've seen this...

It was shown on David Letterman, and he couldn't stop laughing about it. And for good reason. It's the single funniest thing I've ever seen on the web. They guy who made it has done a lot of funny cat videos as well. But this is the most hilarious thing ever. It makes me laugh riotously every time I see it. Seriously, it makes me cry with total joy. That dog's "voice" just slays me, and his reactions to the man's cocky voice--with those ears and those lower teeth--are supremely hysterical. I think I could watch this over and over, forever. It's that good.