I don't remember my specific build throughout the game. I ended with this:
Str: 25
Dex: 38
Wil: 20
Mag: 13
Cun: 47
Con: 14
Specializations: Assassin, Duelist
Skills (asterisk denotes not used that much):
Persuade 4
Stealing 1*
Trap-Making 1*
Survival
Poison-Making 2*
Combat Training 4
Combat Tactics 1
Talents:
Rogue
Dirty Fighting, Combat Movement, Coup de Grace
Below the belt, Deadly Strike, Lethality
Lockpick/traps 4
Stealth 2
Dual Weapon:
Dual-Weapon Training, Dual-Weapon Finesse, Dual-Weapon Expert, Dual-Weapon Mastery
Dual Striking*
Dual-Weapon Sweep, Flurry, Momentum, Whirlwind
All 4 assassin talents
The first two Duelist talents*
I had 25 strength because I had a trinket that gave me +2 to all attributes, and 27 strength let me use some really, really good weapons at the end.
My greatest damage dealt was 100 (though that may have come from the Fade, I really don't remember).