Ancient Americas is the best pre-columbian history youtuber. I always watch his videos.

Here are some others I usually watch.

Stefan Milo for anthropology

Dig. for ancient near east topics

PBS spacetime for physics videos

Whats going on with Shipping for updates on the shipping industry

Technology Connections and LaurieWired for random tech stuff

Grant Harting to watch a pharmacist eat random pills

Road Guy Rob for road engineering information

Canned Fish Files to watch a man eat sardines

ESOTERICA for information on history, magic and religious practices.

Crime Pays But Botany Doesnt for botany tours of predominantly the American southwest

Asianometry for random history and tech history videos

Andy Wards Ancient Pottery for learning about historic ceramic practices

Patrick Kelly for healthcare and medical history