I got James Hetfield's pick at Download 2006 with the Master of Puppets artwork on which looks pretty damn cool!
I also got a "Death Magnetic" pick from Kirk and a coffin shaped one from Rob.
Oh yea, and at a Serj solo gig I got one the guitarists picks that fell on the floor in front of me, and when I picked it up, I raised my head and got smacked in the face by another flying pick!
Still fighting for a drumstick, nearly got one from Dave McClain, but instead, in the crush for it, I fell to the floor with about 10 other random people!