So far, after a bit of searching, this is the best You Tube playlist I've come across:

https://www.youtube.com/watch?v=dD4Y...7MLGfc&index=1

About half way through is 'O come, O come, Emmanuel - (Piano/Cello) - The Piano Guys'. It is
spectacular!

https://www.youtube.com/watch?v=iO7ySn-Swwc