The A-12:
It was supposed to be an all-weather, carrier-based stealth bomber.
There are quite a few old timers around here that were present when the news hit that the program was cancelled. They say it was like a death march as everyone marched out to their cars after being laid off en masse.
On a positive note, there was a full scale mockup at the north end of our property for quite a while. They finally moved it a couple of years ago - I'm not sure what they did with it. You used to be able to see it on google maps.