Downloading anywhere near all of YouTube is essentially an impossible task, I'm willing to bet that YouTube doesn't even have every YouTube video downloaded in one physical location.
But I'm not talking modern YouTube. I'm talking 2012 at the absolute latest. And I'm not talking All, I'm talking a representative sample.
If I wanted to recreate the personal experience of true classic YouTube, what channels would you recommend? You know, back when internet videos where obscene, stupid, and uncoordinated, rather than essentially being crowd sourced television. When you could click from two British dudes making brownies wrong, to popular children's video game characters ripping out each other's endtrails, to kittens playing with feathers, without touching the search bar.