[Tywin]

Boaz missed several key competitors.

I therefore submit:

1. Sam "The Slayer" Tarly
2. Podrick "The Tri-Pod" Payne
3. Tyrion "The Halfman" Lannister

Between these three warriors, they have survived the most deadly battles in Westeros, emerging almost unscathed and leaving a trail of death and destruction in their wake. The thousands killed by this trio include a knight of the Kingsguard, a White Walker, and the most powerful High Lord in Westeros.