Garcian's game of Russian Roulette. "This gun holds seven bullets. I'm a professional; You can't fool me, old man."
Mask De Smith headbutting a bullet out of the air. Also, Dan effortlessly dodging the Eye Beam of and subsequently dispatching Handsome Black.
Andrei Ulmeyda seems to get away with blowing up a stadium. Also, the fact that he was able to resist the effects of Heaven Smile for quite a while is awesome.
Dan Smith's showdown with Curtis Blackburn which ends with Dan interrupting Curtis' dying speech by activating the machinery Curtis used to harvest the organs of the girls he abducted to give him a karmic and painful death.
The end of ANGEL is what sticks in the minds of most people, where Kun Lan effortlessly grabs and then rides the momentum of a bullet from Harman's BFG.
And then he does it again, right at the end of LION.
Mask getting killed, the action stopping, and Mask coming back with the ability to unleash a storm of missiles at the enemy.
From the same sequence: Every other one of the Handsome Men who is defeated simply falls over the same way one of the Smiths would if they die. Harman, however, hits his opponent so hard he explodes like a Heaven's Smile.
Dan also shines in his segment, killing his opponent in a single shot.
Mask having the ability to insta-kill several types of Smiles that otherwise require precise shooting to take down.