Non-enhancing item slot
Wouldn't it be sweet if there was one slot for items that added nothing to your characters stats/abilities/etc. and only enhanced the characters appearance?
The slot could be non-specific so you could wear capes, masks, wigs, face paint, robes, etc.
Really the only thing this would add to the game is slightly more diversity in the looks department, but I think it'd be well worth it.
Obvious problem: monsters dropping these useless items instead of useful ones.