I love guitar challenges. I've posted on one before, the Airwolf Challenge
The original internet sensation, Twofun. 59+ Million views at the time of this post!!!
This is the less well known, but the original artist who arranged Canon Rock, JerryC. 5.8 Million views so far.
Latest challenger, mattrach. 9 Million views so far.
Very catchy.
Here's an acoustic version that I like:
By goljadkin. 1 Million views so far.