This month I recorded the Prélude N.1 by H. Villa-Lobos: a piece that I still have to study much longer before it turns out nice, but on which I'm slowly improving. I think this is the most difficult piece that I've tried so far, and when my teacher gave me the score I thought he was just nuts... According to
GuitarBurst this a difficulty 9 piece (out of 20):
The video is
here.
Prélude N.1 by H. Villa-Lobos from Angel de Vicente on Vimeo.