From my Navy days (and not already mentioned here)

Relative Bearing Grease
Sound powered phone batteries
Crank for the forward mast (so we could go under the Chesapeake Bay Bridge Tunnel)
10 Yards of Stern Sheet

Someone tried to get me with a bucket of steam. We had some dry ice on board (for what, I don't remember) so I went to the galley and got some in a bucket. Once they had it, they weren't quite sure what to do with it.

The biggest one in the Army seemed to be grid squares. When I was a Fire Direction Control Section chief, one of my gun chiefs used to send privates up to my truck for grid squares. I decided to pay the guy back so I cut up a piece of chart paper, ensuring the grid lines were visible.