Smasher

Summary
The Smasher is lifted from Mercurial's post on this thread on the Paizo messageboards. All credit goes to him (I've made a few small changes).

This build takes advantage of Sap Mastery and the Scout's ability to deal more frequent sneak attack damage. The character is also very good at stacking the Shaken and Sickened conditions upon foes which amounts to a -4 attack penalty and -4 saves.

Smasher - Half-Orc Rogue 18 /Barbarian 2
Rogue has the Thug and Scout Archetypes.

Barbarian has the Invulnerable Rager archetype.

Stats
Str: 16 (+2 racial bonus, +2 at 11th, 15th, and 17th, +1 at 16th and 20th)

Dex: 14

Con: 14

Int: 10

Wis: 10

Cha: 14 (+1 at 4th, 8th, and 12th)

Traits
For traits, you want:

Berserker of the Society

Opportunistic Gambler

Toothy (racial alternative trait)

What He Looks Like at Level...
From Mercurial:

"At 7th level if you charge or move than 10' between attacks, you'll deal 2d6 (Earthbreaker damage) +6 (Strength) +6 (Power Attack) +3d6 (sneak attack) + 3d6 (Sap Master) +6 (Sap Adept) in non-lethal damage - assuming a non-magical weapon and no critical hits. That's 8d6+18 damage and, again not including magical weapons or any. That also doesn't count Rage or the eventual Touch of Rage ability you'll get through Eldritch Heritage feats and Opportunistic Gambler.

In the teens damage begins to go through the roof. The Earth-breaker is a great weapon because when you get Power of Giants it becomes a 3d6 base damage weapon and you gain reach with it. Also don't forget your bite attack."