For three days, given that I mostly hike, the contents would be minimal. My Golite Jam 2 holds approx 3500 CI of gear which primarily consists of:
The "basic 10"
Silponcho
3L insulated water bladder
Trangia stove, mess kit, & alcohol
Snugpak Jungle Bag
Silnylon 8x10 tarp, and titanium pegs.
Extra paracord
Food. Mostly dehydrated for main meals = no pots to clean
Water filter (Katadyn Vario)
GORP, jerky, sausage, cheese for snacks while on the move.
Knives: fixed or folder, and an Izula around my neck
Small PSK (on person) in case I'm separated from my equipment.