There are three different types of loot containers: Pouches, Chests, and Skull Chests. Skull Chests obviously being the most rare, and the chain of rarity recedes from there.

The Loot Pouch, being the most common, usually doesn't contain much of value; mostly Crude Items, collection valuables, and gold. However, if your luck is good, you may find a nice surprise inside (such as a bright or dark black clothing item or even a Famed item, though highly unlikely).

The Loot Chest, being the second most common, usually has ordinary items: gold, collection valuables, Crude or Common items, and things of the sort. However, you may occasionally find a bright or dark clothing item or even a Famed in these simple-looking wooden chests (on the rarest of occasions, Legendary weapons have been found).

Finally the Loot Skull Chest: what every looter hopes for. Being the rarest and by far the most valued, they can contain just about anything from a Famed or even Legendary weapon to a rare clothing item to sums of gold over 1,000. These are, by far, any looter's best bet at finding a Legendary weapon.