I love tuna in a pouch for backpacking.
I love smoked oysters packed in oil...all that protien and fat makes good energy in a really small package...the cans pack out easier too.

One more note about jerky. If you want to make REAL jerky without the heat (heat is bad) put your marinated meat on furnace filters (the paper kind, not the fiberglass kind!), sandwich them all together and strap them to a box fan. Let it run for 24 hours and you'll have perfect jerky.