The one that got away was a Bowie knife... of course.
I found it in the woods in East Texas in an area that was supposed to have been a battlefield of one of the skirmishes of the Regulator-Moderator War of 1839-1844 or so. I don't know if has any connection to that conflict or not, or exactly how old it is.
When I found it, the blade was severly rusted, and there were just shards left to show it had once displayed stag grips. The brass crossguard was in seriously bad shape.
Not long after that, I moved to Marlin, Texas, to work for the Marlin Democrat newspaper. I took the knife to a local knifesmith there. He cleaned all the rust off it and installed a new brass guard and grips made of slightly aged looking ivory micarta. It cleaned up NICE.
Eight or 10 years after that, short on money, I gave the knife to my brother for a Christmas present. I haven't had the guts to ask him if he would sell it to me until JUST NOW when typing this made me miss it even more. Just placed a call to his answering machine, so we'll see what happens... if he still has it.