Hardest song to play?
One you've never heard/played before.
that's not necessarily true, I have been given sheet music and almost immediately played it on the spot, and I'm not even that great of a sight-reading. I seen people really good at and they will blow you away.
but as to the game.
Ted Greene in general is the best, and before his death arguably the best guitarist on the planet. His books are a must for anyone whose serious (even if you don't like books).
well Paco is Paco this is really a know brainier. He greatly expanded the imposable Sabicas.
the only other instrument I know enough on is the Piano, and I would say something by Franz Liszt due to compositions speed and use of tenths (DAMN THESE SMALL HANDS!!!!! I guess I have to stay with the devil box) or DR. John; the guys rhythm is impeccable
http://www.youtube.com/watch?v=mycNvDcyjEA
*also what does the winner get? I vote for a pony or a pink hula hoop with one of those noise makers. I hope I win, but surprise presents are always nice.