I give my vote for a mixed system:
1) General loot is randomized, even powerful items. So there isn't a big change for the current system.
2) But unique items are placed at special locations or are used for quest rewards.
3) There are unique items for every class or at least overall builds (two-handed, one-handed, dagger, shield, bow, crossbow, wands, staff; heavy armor, light armor, mage clothes).
4) Unique items are really powerful (at least one level above randomized loot). Upgraded normal items can get better than standard unique items, but never better than upgraded unique items.
5) Unique items can be improved by crafting with very rare ingredients to become even more powerful items. Sometimes the very same ingredient can only be used to improve one unique weapon or armor. To get these ingredients you have to look out for special locations or even solve quests and riddles in the "correct" way.
6) Unique items always have a special look and history behind them, making them interesting and enhancing the roleplaying.
I'd be absolutely fine with most of this.
On a side note I have to point that I would vastly prefer if the scaling in power of the loot could be in general far less pronounced.
For all the shit it constantly gets for being "an obsolete ruleset system" it's almost funny how much D&D/D20 got this better than most of the "more modern" rulesets specifically designed for videogames.
The difference between a +1 item (barely magic) and a +5 (divine artifact) was massive in term of potential (there were creatures vulnerable just to weapons of a certain "rank" and so on) and special abilities made a hell of a difference... and YET the scaling was just marginal in term of ramping up with with numbers. Just a more or less significant bonus to hit chance and damage starting from the same default numbers.
No dull idiocies like a end-game weapon doing TWENTY TIMES the damage of a starting one (or more).
EDIT: for anyone ready to jump in and say: "Well, but that's just a matter of flavor, in some games weapons scale a lot and in other they don't" I'd like to point that the second system tends also to marry A LOT better with non-linear design.
You know, when your players are allegedly allowed to approach content with a certain degree of freedom, it's probably a good idea to have in place a system where items DON'T keep to ramp up almost exponentially.
