Current merc I have with my wolf druid:
Wulfgar (such a fitting name):
Crafted Flamberge, full socketed Sha for max ias breakpoints - 50% balefire, 16% spike nova, 16% miasma all on attack
Arreat's Heart
for bloodlust
Boarfrost
Boarfrost
Assault Helmet (Sacred)
Defense: (2238 - 2561) to (2449 - 2803)
(Barbarian Only)
Required Level: 100
Required Strength: 600
Item Level: 120
25% Chance to cast level 40 Ice Bolt Nova on Melee Attack
20% Attack Speed
Adds 63-125 Cold Damage
+(21 to 25)% to Cold Spell Damage
-50% to Enemy Cold Resistance
+10 to Deathgaze
Weapon Physical Damage +90%
+(87 to 114)% Enhanced Defense
(21 to 25)% to Strength
Socketed (4)
50% icebolt nova on attack with 100 cold pierce
High cold
Lamen of the Archbishop
Lamen of the Archbishop
Amulet
Required Level: 110
Item Level: 120
Orb Effects Applied to this Item are Doubled
+4 to All Skills
to help boost icebolt nova and nothing really better has been found yet for him.
Deadfall

Deadfall
Heavy Belt (4)
Defense: (135 - 159) to (178 - 210)
Required Level: 7
Required Strength: 36
Item Level: 19
2% Chance to cast level 2 Shower of Rocks on Kill
1% Chance of Crushing Blow
+(24 to 46)% Enhanced Defense
+(16 to 25) to Strength
Lightning Resist +(11 to 15)%
Socketed (1)
Defense: (485 - 551) to (616 - 700)
Required Level: 24
Required Strength: 62
Item Level: 36
2% Chance to cast level 4 Shower of Rocks on Kill
2% Chance of Crushing Blow
+(69 to 92)% Enhanced Defense
+(36 to 45) to Strength
Lightning Resist +(21 to 25)%
Socketed (2)
Defense: (1270 - 1400) to (1595 - 1758)
Required Level: 41
Required Strength: 218
Item Level: 51
2% Chance to cast level 8 Shower of Rocks on Kill
3% Chance of Crushing Blow
+(115 to 137)% Enhanced Defense
+(56 to 65) to Strength
Lightning Resist +(31 to 35)%
Socketed (2)
Defense: (1918 - 2095) to (2403 - 2626)
Required Level: 50
Required Strength: 436
Item Level: 85
2% Chance to cast level 12 Shower of Rocks on Kill
4% Chance of Crushing Blow
+(138 to 160)% Enhanced Defense
+(66 to 75) to Strength
Lightning Resist +(36 to 40)%
Socketed (2)
for SoR on kill and the other always-useful melee stats
Toorc's Gift

Toorc's Gift
Chain Gloves (4)
Defense: (26 - 30) to (47 - 54)
Required Level: 5
Required Strength: 28
Item Level: 10
2% Chance to cast level 1 Glacial Nova on Melee Attack
5% Attack Speed
Stun Attack
+(12 to 29)% Enhanced Defense
Cold Resist +(11 to 15)%
Socketed (1)
Defense: (155 - 172) to (211 - 234)
Required Level: 22
Required Strength: 57
Item Level: 31
3% Chance to cast level 2 Glacial Nova on Melee Attack
15% Attack Speed
Adds (11 to 15)-(16 to 25) Cold Damage
Stun Attack
+(47 to 63)% Enhanced Defense
Cold Resist +(21 to 25)%
Socketed (2)
Defense: (434 - 472) to (573 - 624)
Required Level: 40
Required Strength: 201
Item Level: 51
4% Chance to cast level 3 Glacial Nova on Melee Attack
25% Attack Speed
Adds (36 to 45)-(46 to 63) Cold Damage
Stun Attack
+(81 to 97)% Enhanced Defense
Cold Resist +(31 to 35)%
Socketed (3)
Defense: (657 - 710) to (859 - 928)
Required Level: 48
Required Strength: 402
Item Level: 77
5% Chance to cast level 3 Glacial Nova on Melee Attack
30% Attack Speed
Adds (81 to 100)-(101 to 125) Cold Damage
Stun Attack
+(98 to 114)% Enhanced Defense
Cold Resist +(36 to 40)%
Socketed (4)
for glacial nova on attack to freeze screenwide and goes with lamen and boarfrost cold procs
And currently
Akarat's Trek
Akarat's Trek
Light Plated Boots (Sacred)
Defense: (1960 - 2352) to (2170 - 2604)
Required Level: 100
Required Strength: 625
Item Level: 120
2% Chance to cast level 30 Hammertime on Melee Attack
2% Chance to cast level 30 Thunder Wave on Melee Attack
2% Chance to cast level 30 Thunder Hammer Nova on Melee Attack
(10 to 40)% Movement Speed
+(15 to 20) to Charged Strike
Weapon Physical Damage +(60 to 90)%
+(150 to 200)% Enhanced Defense
10% to All Attributes
+10 to Light Radius
Socketed (4)
for lack of better boots made so far.
All sockets besides weap are Xar runes for 2% max life.
His procs cleaned up all straggler DCows behind me en route to 121. It was incredible. Proc fest, so hopefully your comp could handle it, but fun merc build.
Also just thrown together, but it worked well.
Edit: all orbed with % Total Char Defense.