Many of my early yoga experiences came from Yogamazing: https://www.youtube.com/user/yogamazing
And Yoga with Adriene has quickly become a favorite among my friends: https://www.youtube.com/user/yogawithadriene
My recommended Chair Yoga videos.
My go-to is the Nike Training Club app.
When I’m in a rush or need an extra push, I usually find something from Popsugar Fitness.