I would've liked to have seen Diablo's item finding go like this:
A lot of unique items would be forged by a blacksmith or something in a town much like Griswold in D1. These would be your safe bet items, maybe not top of the line, certain rare items and their mods could beat them out, but still nevertheless great and are mostly static in their affixes.
Then some unique items that drop from monsters are very, very good, but because it comes from a demon from Hell there's a high chance it is corrupted and cursed. D1 flirted with this idea that some items had drawbacks, and I'd have loved to see that explored more. Wearing the Undead Crown slowly drains you of your life but allows you greater command of more high level undead, Duriel's Shell provides great fire resistance but at the cost of chilling/randomly immobilizing you, the Butcher's Cleaver provides massive physical damage but it cannot be used with a shield and is notoriously slow, etc.
Maybe you could find ways to lift the curse from these items by having a Holy figure bless it to purge it of its wickedness or something. Due to the strength of evil that is within it, this would require great willpower and would only be able to be done a limited amount of times per difficulty from that NPC. Any further would require a lucky encounter with a shrine.
Obviously this shit will never happen but I always thought it would have been cool and thematically fitting.