I subscribe to 2 Feet Forward, Abbie Barnes, Darwin on the Trail and Homemade wanderlust, all great channels.
Others I like -
Wayne Fenton - British couple doing the PCT in the US.
Adventure Archives - Another USA one (sorry!) but a different vibe from most others, long videos and slow walking!
Dean Read - UK based, mostly around the Peak District.
Evan's Backpacking videos - US guy did the Appalachian trail this year.