The following are some good China and/or Chinese language related channels, in no particular order.
Mandarin
https://www.youtube.com/channel/UC3pGw6kat2Bkep6Wh_atAgw
TV Series
https://www.youtube.com/channel/UCteBLoijWzlVFSR5BBtS_2Q
阿木爷爷
https://www.youtube.com/channel/UClaEdLrmti779-tyovta8zw
说说中文
https://www.youtube.com/channel/UC_Aiv9xguPQxZ6msnNoz3HQ
Zero头Hero
https://www.youtube.com/channel/UCQ3IlLg5VGeydxtswBoyt6A
Fragrant Mandarin
https://www.youtube.com/channel/UCVk35GjhYmoupCwWbaag1FA
Mandarin Corner
https://www.youtube.com/channel/UC2fAiRQHRQT9aj9P_ijYeow
Centoriente (Growing Up with Chinese)
https://www.youtube.com/c/Centroriente1981/featured
Hit Chinese
https://www.youtube.com/channel/UCv33mxPEDfd_Ee1pz1y8KLw
Slow & Clear Chinese
https://www.youtube.com/channel/UCdwdSGQsSbcapDmODtOr58g
Chinese TV
https://www.youtube.com/channel/UC2Ce9ttakhococ7GhOzyONA