There were several "hard-to-find" figures in the POTF2 line. Which one(s) were the hardest/most satisfying to finally get?

For me, I'd go with either R2 w/holo Leia or DV: Removable Helmet. R2 because it took about 1 1/2 yers, and Vader 'cause it was at retail instead of several collectible shops that had it for $20.