Incidental loot is a good point, but finding gold on a wolf still does not feel authentic. We could find that gold on a dead body nearby instead. While with a human enemy, it would be normal to find some of that incidental loot on himself. It depends on the enemy.
Random vs Determined is also a valid question, and in this regard, I personally prefer the loot to be mostly predetermined. May be a little randomization to help with variety.
But the original poll remains justified, I selected the 3rd option, I like the Infinity engine system. It makes sense that i can pick whatever weapon or item that enemy was carrying. Receiving a lot of stuff feel rewarding too.
Ability to loot everything can be long and tedious if you have a lot of bodies to check, though, and the inventory could get filled quickly, so there is room for some adjustments. I think it can be improved already by a good user interface for loot and inventory, and also shop interface, so having many items does not bring annoying inventory management.
a small loot window which does not take all the screen, and auto closes when i move away.
An inventory that sort items intelligently (pocket for craft materials, pocket for gems, weapons slots...).
Easy way to sell many items at once. ( In Baldur's gate : select all items you want to sell, click sell. In NWN 2: drag and drop, select quantity, click OK... repeat ).
There is another thread about inventory in the forum, but I think the 2 questions are linked.
Also in a related note, something I do not like in neverwinter nights games : when you kill some enemy, you would have to wait a few seconds until the body disappear. After that a bag containing the loot would appear. First it's slow, and second it does not feel authentic, I would prefer the body to stay visible, at least until I leave the area.