Ideally some way to quickly sort the inventory by category is important (e.g. break it down into Weapon, armor, consumables, crafting materials, quest items, etc.).
But I guess part of that goes beyond how it's presented / organized… Some RPGs throw way too much junk at you (stuff that has no use other than to sell to merchants)… Just give me the gold / cash. Of course, I suppose I could just not take it but if it's in every chest / corpse you come across, that's hard to avoid. DOS's issue is that there's just too much loot (e.g., all these magic items with tiny differences between them and 10 million crafting materials) that make inventory management tedious… I don't think any tweaks to inventory / UI can really overcome boring loot.
In general, I prefer a minimalistic UI design. Just tell what I need to know and don't clutter the screen with pretty HUD, as I'd rather see more of the game world. Or options to turn some or all of it off are always nice, too.