Depends on the trip and terrain but my guidelines goes like this:
Less than 24hr:
Belt rig, ammo, either Camel back or canteen, Med pack, knife, dump pouch (garbage shells anything else) gun on a sling, Gloves, hat, soft shell jacket, para cord 50', power snacks, matches, compass.
More than 24 hr:
3 day pack (no bigger than a kids nap sack), belt, all the same, add in my hatchet or saw, sleeping back real food plus power snacks and both camel and canteen. I build my own shelter. Map
More than 36hr.
Will post later as it's a long list more to go wrong. Flares always remember the flares.
I am a firm believer (not right or wrong) that less is more, I would rather use my head than carry 50lbs of gear and get into more trouble with exhaustion, tripping, falling and distress. In avalanche survival I had to go 5 days with just my belt setup, granted there was no shortage of snow for water and had a shovel. People get in more trouble not stopping and thinking through things than not having the right items in their pack.