what are the hardest songs you guys know on guitar? im intrested in learning some technical ones, lets see what you guys got.

ive had a friend who had some major problems with figuring out Crying Lightning from Arctic Monkeys.
for me it works

Bleed

Hmmmmmmm............

TBH - none are hard now I know them xD But i will tell you the ones that gave me the most trouble

LedZep - Stairway To Heaven. I just could not get it, was so angry for like 2 weeks - then I realised "form the chord, play the notes" and now tis easy.
Lamb of God - Laid To Rest. Again, fuckin hard at first because Lamb of God like to bounce around the fretboard which, while interesting and exciting, is not fun to learn until you start to get to grips with it.
Killswitch Engage - pretty much all of it. Alternate picking like a maniac, lots of hammer/pulloffs make for speedy and again, exciting playing. Still gives me trouble to this day.

Slayer............. Nah, I lied. Slayer isn't hard lol

Animals as Leaders - Cafo
Animals as Leaders - Earth Departure
Periphery - Zyglrox

There's something to work out with.