Quite possibly the hardest Guitar Hero song has officially being "FCd."
The special honors go to Iamchris4life, for reaching this milestone.
Official thread at Score Hero Crazy!
Interesting things to note: "One" is the only song on Guitar Hero 3 yet to be FC'd on Expert.
Through the Fire and Flames is also yet to be FC'd on Hard. :\
Edit: The video is now available for you to see here