Dream: Helm Rune Word - Diablo 2
Dream is one of the most commonly used high level Rune Words for the Helm slot due to Holy Shock Aura along with all of the survivability and Mana bonuses that it offers. The only other high level Helm Rune Word is Delirium and it sucks due to the Chance of Hit Delirium affect. You can also put this Rune Word into a Shield and it's worth noting that wearing a Dream Helm + Dream Shield will stack the Holy Shock Aura (so it will be Skill Level 30). This only works in the 1.14d version of the game, however.
There is an entire Paladin build centered around stacking this Aura called the Tesladin since they're able to amplify the damage of this aura even further by loading skill points into the synergies. Unless you're doing the Tesladin build it is generally not recommended you stack Dream like this though.
Keep in mind that all Rune Words you create will retain any pre-existing bonuses found on the item. If you find a 'Superior' piece of armor with +Enhanced Defense, a Superior Weapon with +Enhanced Damage or a Helm/Weapon that has +Skill bonuses for a certain class, all of these will remain on the final Rune Word that is created. It's also possible to 'ebug' a piece of Ethereal Armor that you find which will increase the Defense bonuses by 50%, check out my Ebugging Guide for more information.
Farming High Runes: Out of all locations in the game one stands above the rest for farming specifically High Runes, the Countess during Act 1. The Countess has a guaranteed chance to always drop a High Rune and can even drop more than one. Check out my The Countess Farming Guide for more information.
Required Runes: Io -- Jah -- Pul
Level Req: 65
Other Req: Ladder Only
Slots: Helm and Shields
10% Chance To Cast Level 15 Confuse When Struck
Level 15 Holy Shock Aura When Equipped
+20-30% Faster Hit Recovery (varies)
+30% Enhanced Defense
+150-220 Defense (varies)
+10 To Vitality
+(0.625*Clvl) To Mana (Based On Character Level)
All Resistances +5-20 (varies)
12-25% Better Chance of Getting Magic Items (varies)
Increase Maximum Life 5%
+50 To Life