2 pins have been the hardest for me, one I have one I don't. My hardest pin so far was my first holy grail, the WDW PTP, and like others on this thread it was T-Mom (Lisa) who finally traded me for it. My second is needed to complete a set that, thanks to Nat, is a whole lot closer to completion. All I need now to finish my 2000 Innoventions set is the Xerox pin.