What is the one card from a set that has yet to surface?

[captainbohica]

Anyone know what is the hottest, or most wanted card from any set, that has yet to surface?

[SHowley2003]

There has to be some of the big 1/1s from Marvel Masterpieces that have yet to surface. Or some of the 1/1s from the recent Metal products. I know there are certain Wolverine, Spiderman, Venom, etc. base cards that became the preferred cards from those various sets and as a result the PMGs and other parallels became big chase cards. I don't know which ones, but I'd love to learn which 1/1s are still being sought after.