I’d argue there are more than just VMagi/Duriel’s/Skullders with respect to being viable for a Unique Armor. I’d use Guardian Angel any day of the week(if not for me then for my mercenary). +Block and +Max Resist is so hard to come by provided you got +Resistance elsewhere to take advantage of it. Ditto Shaftstop/Leviathan for DR% although latter requires -Requirements Jewel or Hel rune. Gladiator’s Bane, Spirit Shroud and Que-Hegan are also underrated.
That being said, I agree that Unique Armor could use some buffs, if not considerable ones like the one I proposed for Tyreal’s. If Tyreal’s got Fanaticism, I’d make it my goal every ladder to find one for either an Avenger Paladin or a Frenzy Barbarian.