I would be elated to find an early Civil War cache of coins. Lots of stories in my area about people burying gold and silver coins to protect their savings from all the looting that was going on here during the war. Sadly, I believe that 99.99% of the caches (if the stories were even true) were recovered by the family that buried it when things were safe.
I've never found an intact pocket watch, bits and pieces but nothing whole or even recognizable as a pocket watch. Believe it or else, even with all the cool coins out there I've yet to dig...my answer would be a whole pocket watch.
Rumor and legend has it a Revolutionary War cannon stuffed with gold coins by a British General was lost in a semi-local swamp (near Rome, NY). That would be a good thing to uncover.