The best sets of Heavy Armor - Elder Scrolls: Morrowind
In Elder Scrolls: Morrowind Heavy Armor is generally considered the second best armor skill in the game. Heavy Armor offers you the most protection out of all armor skills and (for the most part) Heavy Armor has higher Enchantment Values on the gear than with Medium/Light Armor. This will allow you to put more powerful enchants on your gear with heavy than with medium or light.
The biggest draw back to Heavy Armor in Morrowind is the weight. Unless you put Feather Enchantments on your gear or use Feather Potions you'll constantly be fighting for free space in your inventory. For this reason Heavy Armor is generally only recommended for characters who will be doing a lot of melee fighting.
Best Armor Rating Per Slot
Helm: Helm of Oreyn Bearclaw
Chest: Dragonbone Cuirass or Lord's Mail
Legs: Daedric Greaves
Boots: Ten Pace Boots // Daedric Boots
Pauldrons: Daedric Pauldrons
Bracers: Fists of Randagulf or Wraithguard
Shield: Eleidon's Ward
Important: The Armor Ratings you see in my screenshots below may be different for you. The amount of Armor Rating a piece of gear gives you in Morrowind decreases or increases depending on what your skill level is with that armor.
Ebony Armor is the second best set of Heavy Armor in Morrowind, it has high Armor Rating per piece as well as a high weight value. Another bonus of Ebony Armor -- and most Heavy Armors is that each piece has a high Enchantment Value (meaning you can put good enchants on it or many enchants).
Daedric Armor is the only set better than Ebony and it outclasses Ebony Armor in virtually every way. The main upside for Ebony Armor is it's much easier to get your hands on a full set of it than Daedric Armor. You can find Ebony Armor pretty commonly from Daedric Shrines along with many other places.
An enchanted Ebony Cuirass with Restore Fatigue.
Daedric Armor is the best set of Heavy Armor in the game along with the heaviest. Unlike most other sets of armor in this game, there is also only a single place to get (almost) an entire set of Daedric Armor, from Divayth Fyr in Tel Fyr. The downside of this is Divayth Fyr is involved in the main quest for Morrowind and killing him will break the main quest.
Aside from Divayth Fyr there are about a dozen different locations where you can find Daedric Armor but you'll rarely find more than one or two pieces at a time. Check my Locations of all Daedric Armor page for more information.
Mournhold - Her Hands Ordinator Armor
The Her Hands Heavy Armor set is a unique set of gear that can only be obtained in the Tribunal Expansion from killing one of Almalexia's Royal Guard. You can find these unique High Ordinators all throughout the town of Mournhold, they're the Ordinators with reddish gear instead of the usual yellowish gear they wear. Check my screenshot above to see what I am talking about.
Much like with all NPCs you plan to kill you'll want to either Taunt them or use Frenzy Humanoid to provoke them into attacking you. This will allow you to fight them 1 on 1 and also allow you to avoid any criminal penalty for attacking them. If you want Her Hands armor - you have to kill one of these NPCs to get it.
Her Hands armor comes fully enchanted already which is both a perk of the armor as well as a draw back. I'd argue that all of the enchants on the armor are pretty good... however you lose the ability to choose which enchants you want.