Thats a good question there, if I could only subscribe to one person it would be this guy:
He's from Texas and does survivalist videos on how to survive in disaster situations and does reviews of the things you would use in such a situation even down to the basics like the kind of things you could use for cooking or building for cooking if they're not around.
Whilst I am not into watching survival and disaster preparedness videos all the time, I find his channel very interesting. It's good to know what to do in a disaster situation and his videos make you think about what to do in them sort of situations. He talks about things going on in the world too like rainfall affecting crops, natural disasters in history etc
You could say he's a more in depth Bear Grylls but without the crazy climbing/stunts.
Heres a few videos by him: